NZ243514A - Acylated n-(aminoalkylcarbonyl)pyrrolidine and thiazolidine derivatives, preparation and pharmaceutical compositions thereof - Google Patents

Abstract

Compounds of formula: <IMAGE> their salts, their preparation and the medicaments containing them.

Description

New Zealand Paient Spedficaiion for Paient Number £43514 24 3 5 1 A No.: Date: Priority Date{s): Coifijjloivi S,;c31 \ ,p ' -j / Cap r: SSTtK-SC<rfpQ.0"/{<?$. W.QM .UL;< co^p X^C-V;. codify .4-7V.

Publication Date: .. 4® n '^nrngl, No; Class Cont: C,9lC^'.T\l<*h NO. .DRAWINGS NEW ZEALAND PATENTS ACT, 1953 COMPLETE SPECIFICATION PYRROLIDINE, THIAZOLINE AND PIPERIDINE DERIVATIVES, ^ THEIR PREPARATION AND MEDICAMENTS CONTAINING THEM We, RHONE-POULENC RORER SA, a French body corporate, of 20 Avenue Raymond Aron, F 92160, Antony, France hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- (followed by page - la -) 24 3 5 1 la The present invention provides, as new compounds, the pyrrolidine derivatives of formula: RiA r n I (I) co-ch— nh-co-r3 i ^ in which - either R represents a methylene, ethylene, SO, S02 or CHOH radical or a sulphur atom, R, represents a pyridyl radical optionally substituted by one or more alkyl radicals, a furyl radical optionally substituted by one or more alkyl radicals, a thienyl radical optionally substituted by one or more alkyl radicals, a quinolyl radical optionally substituted by one or more alkyl radicals, a naphthyl radical optionally substituted by one 15 or more alkyl radicals, an indolyl radical optionally substituted by one or more alkyl radicals, or a phenyl radical optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy, hydroxyl, nitro, amino, monoalkylamino, dialkylamino, alkoxycarbonyl, 20 -CO-NR7R8, -NH-CO-CHj, trifluoromethyl and trifluoromethoxy radicals, and Rs represents a hydrogen atom, - or R represents a methylene radical, R, represents a hydrogen atom and R5 represents a phenyl radical, - or R represents a radical CHR^ and R, and R5 each 24 3 5 represent a hydrogen atom, - R, represents an alkoxycarbonyl, cycloalkyloxy-carbonyl, cycloalkylalkyloxycarbonyl, -CONR^Rjq or phenyl radical optionally substituted by one or more substituents chosen from alkyl, alkoxy and hydroxyl radicals, - R3 represents a phenyl radical (optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy and alkylthio radicals), or a naphthyl, indolyl, quinolyl or phenylamino radical, the phenyl ring of which is optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy, alkylthio, trifluoromethyl, carboxyl, alkoxycarbonyl, hydroxyl, nitro, amino, acyl, cyano, sulphamoyl, carbamoyl, hydroxyiminoalkyl, alkoxyiminoalkyl, hydroxyamino-carbonyl, 15 alkoxyaminocarbonyl, 5-tetraEolyl, 5-tetrazolylalkyl, trifluoromethyl-sulphonamido, alkylsulphinyl, mono- or polyhydroxy-alkyl, sulpho, -alk-O-CO-alk, -alk-COOX, -alk-O-alk, -alk'-COOX, -O-alk-COOX, -CH=CH-COOX, -CO-COOX, -alk-SOjH, optionally in the form of a salt, -CH=CH-alk', -C(=NOH) -COOX, -S-alk-COOX, -0-CH2-alk'-COOX, -CX=N-0-alk-C00X, -alk-N(OH)-CO-alk and 2,2-dimethyl-4,6-dioxo-l,3-dioxan-5-yl radicals, - R4 represents a hydrogen atom or an alkyl radical, - Ra represents a phenyl radical, 2 5 - R7 represents a hydrogen atom or an alkyl, phenyl-alkyl or phenyl radical optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy £ e 24 3 5 1 4 and alkylthio radicals, - R8 represents an alkyl, phenylalkyl or phenyl radical optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy and alkylthio radicals, or R7 and Rg form with the nitrogen atom to which they are attached a mono- or polycyclic saturated or unsaturated heterocycle containing 4 to 9 carbon atoms and one or more hetero atoms (preferably 0, N or S) and optionally substituted by one or 10 more alkyl radicals, - Rs represents a hydrogen atom or an alkyl, cycloalkyl-alkyl, cycloalkyl, phenylalkyl or phenyl radical optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy and alkylthio radicals, - RI0 represents an alkyl, cycloalkylalkyl, cycloalkyl, phenylalkyl or phenyl radical optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy and alkylthio radicals, or R^ and R10 form together with the nitrogen atom to which 20 they are attached a mono- or polycyclic saturated or unsaturated heterocycle containing 4 to 9 carbon atoms and one or more hetero atoms (preferably 0, N or S) and optionally substituted by one or more alkyl radicals, - X represents a hydrogen atom, an alkyl or phenylalkyl 25 radical, - alk represents (when monovalent) an alkyl or (when divalent) an alkylene radical, O* 2 4 3 5* - alk' represents (when monovalent) a hydroxyalkyl or alkoxyalkyl radical or (when divalent) a hydroxyalkylene or alkoxyalkylene radical, and their salts, and their racemic mixtures and enantioners when they comprise at least one 5 asymmetric centre.

In the preceding definitions and in those cited below, unless otherwise mentioned, the alkyl, alkylene and alkoxy radicals and the alkyl, alkylene and alkoxy moieties contain l to 4 carbon atoms each in a straight or branched 10 chain, the acyl radicals or moieties contain 2 to 4 carbon atoms each and the cycloalkyl radicals and moieties contain 3 to 6 carbon atoms each.

When R7 and R^ form a heterocycle with the nitrogen atom to which they are attached, the latter is 15 preferably a piperidino ring optionally substituted by one or more alkyl radicals or a 1,2,3,4-tetrahydro-quinoline ring.

When R9 and R)0 form a heterocycle with the nitrogen atom to which they are attached, the latter is 20 preferably a piperidino ring or a 1-perhydroazepinyl, 1, 2,3,6-tetrahydro, 1-pyridyl, 1,2,3,4-tetrahydro-l-quinolyl, l-pyrrolidinyl, 1,2,3,4-tetrahydro-2-isoquinolyl, thiomorpholino or 1-indolyl ring, these rings being optionally substituted by at least one alkyl radical. 25 The compounds of formula (I) having one or more asymmetric centres display isomeric forms. The racemic mixtures and the enantiomers of these compounds are within the scope of the invention.

The compounds of formula (I) in which R represents a methylene, ethylene, CHOH or CHR« radical or a sulphur atom and R3 represents a phenylamino radical, the 5 phenyl ring of which is optionally substituted, may be prepared by reaction of a reactive derivative of carbamic acid, obtained optionally in situ by action of a reactive derivative of carbonic acid chosen from N,N'carbonyl-diimidazole, phosgene, diphosgene and p-nitrophenyl 10 chloroformate on a derivative of formula: (II) in which R represents a methylene, ethylene, CHOH or CHRa radical or a sulphur atom and R,, R2, R4, Rs and R$ have the same meanings as in formula (I), with an aniline in which 15 the phenyl ring is optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy, alkylthio, trifluoromethyl, carboxyl, alkoxycarbonyl, hydroxyl, nitro, amino, acyl, cyano, sulphamoyl, carbamoyl, hydroxyiminoalkyl, alkoxyiminoalkyl, hydroxyaminocarbonyl, 20 alkoxyaminocarbonyl, 5-tetrazolyl, 5-tetrazolylalkyl, trifluoromethylsulphonamido, alkylsulphinyl, mono- or polyhydroxyalkyl, sulpho, -alk-O-CO-alk, -alk-COOX, 24 3 5 -alk-O-alk, -alk'-COOX, -O-alk-COOX, -CH=CH-COOX, -CO-COOX, -alk-SOjH, -CH=CH-alk', -C(=NOH)-COOX, -S-alk-COOX, -0-CH2-a lk'-COOX, -CX=N-0-alk-C00X/ -alk-N(OH)-CO-alk and 2,2-dimethy1-4, 6-dioxo-l,3-dioxan-5-yl radicals.

This reaction is generally carried out in an inert solvent such as tetrahydrofuran, dimethylformamide, a chlorinated solvent (chloroform, 1,2-dichloroethane for example) or an aromatic solvent (benzene, toluene for example), at a temperature between 20°C and the boiling 10 point of the solvent.

The reactive derivative of carbamic acid may be obtained under the same solvent and temperature conditions.

The derivatives of formula (II) may be obtained by deprotection of a derivative of formula: r r ■r5 1 \ x r? 1 N 2 I co-ch — nh-cooc(ch3)3 (ill) R/i in which R represents a methylene, ethylene, CHOH or CHRg radical or a sulphur atom and Rw R2, R,, R5 and R$ r '\ 3 5 1 7 have the same meanings as in formula (I).

This deprotection is preferably carried out using iodotrimethylsilane in an inert solvent such as a chlorinated solvent (chloroform, 1,2-dichloroethane for 5 example), at a temperature between 15 and 40®C.

The derivatives of formula (III) may be obtained by action of a derivative of formula: R [—R5 h in which R represents a methylene, ethylene, CHOH or 10 CHR6 radical or a sulphur atom and R:, R2, R5 and R6 have the same meanings as in formula (I), on an acid of formula: HOOC-CH-NH-COOC(CH3)3 (V) R, in which R«, is defined as in formula (I).

This reaction is carried out in an inert solvent such as acetonitrile, tetrahydrofuran or a chlorinated solvent, in the presence of a condensation 20 agent used in peptide chemistry such as carbodiimide (for example N,N'-dicyclohexylcarbodiimide) or an alkyl chloroformate, at a temperature between 10 and 40°C.

The derivatives of formula (V) may be obtained by the usual methods of aminoacid 25 protection. 8 a The derivatives of formula (IV) may be prepared by application or adaptation of the methods described in the literature and of the methods described below.

The derivatives of formula (IV) for which R2 represents an alkoxycarbonyl, cycloalkyloxycarbonyl or cycloalJcylalkyloxycarbonyl radical may be obtained by esterification of an acid of formula: in which R represents a methylene, ethylene, CHOH or CHR5 radical or a sulphur atom and R:, R5 and R6 have the same meanings as in formula (I). using an R13-0H alcohol in which R13 represents an alkyl, 15 cycloalkyl or cycloalkylalkyl radical, in acid medium, at the boiling point of the reaction mixture. For compounds of formula (IV) for which R2 represents a tert-butoxycarbonyl radical, isobutene is reacted with a product of formula (VI) in an inert solvent such as a 20 chlorinated solvent, in the presence of an acid such as sulphuric acid, at a temperature in the vicinity of 20°C. represents a methylene radical and Rx and R5 are defined (VI) H This esterification is generally carried out The derivatives of formula (VI) for which R 9 as in formula (I) may be prepared by application or adaptation of the method desribed by H. GERSHON et al., J. Org. Chem., 26, 2347 (1961).

The derivatives of formula (VI) for which R 5 represents a CHR6 radical and Rlf R5 and R6 are defined as in formula (I) may be prepared by application or adaptation of the method described by J.K. THOTTATHIL et al., Tetrahedron Letters, 27, 151 (1986), and D.R. KRONENTHAL et al., Tetrahedron Letters, 31, 1241 10 (1990).

The derivatives of formula (VI) for which R represents a methylene radical, Rx represents a hydrogen atom and R5 represents a phenyl radical may be prepared by application or adaptation of the method described by 15 Y.N. BELOKON et al., J. Chem. Soc. Perkin Trans 1, 2075 (1988) and J. RIVIER and G.R. MARSHALL, Peptides, Chemistry, Structure and Biology, Proceedings of the Eleventh American Peptide Symposium, July 9-14, 1989 -La Jolla California USA - ESCOM Leiden 1990. 20 The derivatives of formula (VI) for which R represents a sulphur atom, Rx is defined as in formula (I) and R5 represents a hydrogen atom may be obtained by action of a derivative of formula: HS-CH-CH-NH2 (VII) R5 COOH in which Rs represents a hydrogen atom, on an aldehyde of formula: Ri-CHO (VIII) 24351 in which R, has the same meaning as in formula (I) .

This reaction is preferably carried out in an alcohol, at the boiling point of the reaction mixture.

The derivatives of formula (VI) for which R 5 represents an ethylene radical, R, is defined as in formula (I) and R5 represents a hydrogen atom may be prepared by reduction of the derivatives of formula: hydrogen, in an inert solvent such as an alcohol, in the presence of a catalyst such as platinum oxide, at a temperature between 20 and 100°C, optionally under pressure or using sodium borohydride and potassium carbonate in the 15 water-alcohol mixture (preferably ethanol), at a temperature between 0 and 2 0°C.

The derivatives of formula (IX) may be obtained by action of an alkyl acetamidomalonate on a derivative of formula: (IX) in which Rj has the same meaning as in formula (I) .

This reduction is generally carried out using —0 ch2 — ch2-ch2ci (X) in which R, has the same meaning as in formula 11 (I), followed by hydrolysis, decarboxylation and dehydration of the product obtained by heating in aqueous hydrochloric acid, the action of the alkyl acetamidomalonate on the product of formula (X) being 5 carried out in an alcohol, in the presence of a base such as an alkali metal alkoxide, at the boiling point of the solvent.

The derivatives of formula (X) may be obtained by application or adaptation of the method 10 described by M. T. WILLS et al., J. Org. Chem., 45 (12), 2495 (1980).

The derivatives of formula (IV) may also be obtained by deprotection of a derivative of formula: *5 R1 fg R2 (XI) COOZ in which R represents a methylene, ethylene, CHOH or CHR6 radical or a sulphur atom, Rlt R2, R5 and R6 have the same meanings as in formula (I) and Z represents an alkyl radical and preferably tert-butyl, it being understood that when R2 represents a tert-butoxycarbonyl 20 radical, Z cannot be a methyl or an ethyl radical.

This reaction is carried out in an inert solvent such as a chlorinated solvent, using iodotrimethylsilane, at a temperature between 15°C and the boiling point of the reaction mixture. 12 The derivatives of formula (XI) for which R represents a methylene radical, R2 represents a phenyl, optionally substituted 2-thienyl, optionally substituted 2-furyl or optionally substituted 3-indolyl 5 radical, R2 represents an alkoxycarbonyl, cycloalkyloxycarbonyl, cycloalkylalkyloxycarbonyl radical and R5 represents a hydrogen atom may be obtained by action of a derivative of formula: R,H (XII) in which R: represents a phenyl, optionally substituted 2-thienyl, optionally substituted 2-furyl or optionally substituted 3-indolyl radical, on a derivative of formula: r r-r5 1 1 r"-^n>-r2 Y (XIII; cooz in which R represents a methylene radical, R2 and R5 have the same meanings as above, Rn represents an alkoxy radical containing 1 or 2 carbon atoms and Z represents an alkyl radical.

This reaction is generally carried out in the 20 presence of a strong acid such as p-toluenesulphonic acid or a Lewis acid such as aluminium trichloride, optionally in an inert solvent such as an aromatic solvent, at a temperature between 20°C and the boiling point of the reaction mixture. 24 3 5 13 The derivatives of formula (XIII) may be prepared by application or adaptation of the method described by T. SHONO et al., J. Am. Chem. Soc., 104, 6697 (1982).

The derivatives of formula (XI) for which R2 represents an alkoxycarbonyl, cycloalkyloxycarbonyl or cycloalkylalkyloxycarbonyl radical and Z represents a tert-butyl radical may be prepared by esterification of an acid of formula: in which R represents a methylene, ethylene, CHOH or CHRS radical or a sulphur atom and Rx, R5 and R6 have the same meanings as in formula (I).

This esterification is carried out under the 15 conditions described above for the esterification of the acids of formula (VI) or using an alcohol, in the presence of tosyl chloride, in pyridine.

The acids of formula (XIV) may be obtained by action of ditert-butyl dicarbonate on an acid of 20 formula (VI).

This reaction is carried out in an inert solvent such as water, dioxan or a mixture of these solvents, in the presence of an alkali metal carbonate, at a temperature in the vicinity of 20°C.

(XIV) cooc(ch3)3 ' J I 'i 14 The derivatives of formula (XI) for which R2 represents a -CONRgR10 group and Z represents a tert-butyl radical may be obtained by reaction of an acid of formula (XIV) or a reactive derivative of this acid 5 with an amine of formula: HNR9R10 (XV) in which Rg and R10 have the same meanings as in formula (I)- When using the acid, the operation is carried 10 out in the presence of a condensation agent used in peptide chemistry such as a carbodiimide (for example N,N'-dicyclohexylcarbodiimide) or N,N'-carbonyl-diimidazole, in an inert solvent such as an ether (tetrahydrofuran, dioxan for example), an amide 15 (dimethylformamide) or a chlorinated solvent (methylene chloride, 1,2-dichloroethane, chloroform for example) at a temperature between 0°C and the reflux temperature of the reaction mixture.

When using a reactive derivative of the acid, 20 it is possible to react the anhydride, a mixed anhydride or an ester (which may be chosen from among the activated or nonactivated esters of the acid).

The operation is then carried out either in an organic medium, optionally in the presence of an 25 acid acceptor such as a nitrogen-containing organic base (trialkylamine, pyridine, 1,8-diazabicyclo[5.4.0]-7-undecene or l,5-diazabicyclo[4.3.0]-5-nonene for example), in a solvent such as mentioned above, or in a mixture of these solvents, at a temperature between 0°C and the reflux temperature of the reaction mixture, either in a two-phase water/organic medium in the presence of an alkaline or alkaline earth base (sodium hydroxide, potassium hydroxide) or of an alkali metal or alkaline earth metal carbonate or bicarbonate at a temperature between 0 and 40 °C.

The derivatives of formula (IV) for which R represents a methylene radical, R: is defined as in the general formula (I) with the exception of radicals or substituents which may have been altered during a reduction (for example the quinolyl radical or the nitro substituent), R2 represents a phenyl radical optionally substituted by one or more radicals chosen from among the alkyl, alkoxy and hydroxyl radicals and R5 represents a hydrogen atom may be obtained by application or adaptation of the methods described by C.G. OVERBERGER et al., J. Amer. Chem. Soc., £1 887 (1969). This method involves pyrrole reductions which may be obtained by application or adaptation of the methods described in Synthesis, 613 (1991), Tetrahedron Letters 4407-4410 (1986).

The derivatives of formula (IV) for which R represents a methylene radical, Rj represents a phenyl radical optionally substituted by one or more radicals chosen from among the alkyl, alkoxy and hydroxyl radicals or the optionally substituted naphthyl radical and R2 represents a phenyl radical optionally 16 substituted by one or more radicals chosen from among the alkyl, alkoxy and hydroxyl radicals and Rs represents a hydrogen atom may also be obtained by reaction of ethylene with a derivative of formula: 5 R,-CH=N-CH2-R2 (XVI) in which R: and R2 have the same meanings as above.

Ethylene may be formed in situ by decomposition of tetrahydrofuran in the presence of a base such as butyllithium, at a temperature between 0 10 and 25°C. Ethylene may also be added, in the presence of lithium diisopropylamide, in tetrahydrofuran at a temperature in the vicinity of 20°C.

The derivatives of formula (XVI) may be obtained by action of an aldehyde of formula (VIII) in 15 which R, has the same meaning as above on an amine of formula: R2-CH2-NH2 (XVII) in which R2 has the same meaning as above.

This reaction is generally carried out in an 20 inert solvent such as a hydrocarbon (benzene, toluene for example), a chlorinated solvent (dichloromethane, chloroform for example), optionally in the presence of p-toluenesulphonic acid, at the boiling point of the reaction mixture.

The compounds of formula (IV) for which R represents a methylene or CHOH radical, Rj represents a pyridyl, naphthyl, quinolyl or phenyl radical, R2 represents an alkoxycarbonyl, cycloalkyloxycarbonyl, L ^ 5 jlaiy i *.•" V 17 cycloalkylalkyloxycarbonyl or phenyl radical optionally substituted by one or more substituents chosen from among the alkyl, alkoxy or hydroxyl radicals and Rs represents a hydrogen atom may be obtained by reduction 5 of a derivative of formula: in which R, R: and R2 have the same meanings as above. using hydrogen, in the presence of a catalyst such as 10 platinum oxide, in an inert solvent such as ethanol at a temperature in the vicinity of 20°C, or using sodium borohydride and potassium carbonate in a water-alcohol mixture (preferably ethanol), at a temperature between 0 and 20°C.

The derivatives of formula XVIII may be obtained by application or adaptation of the methods described by A. MKAIRI and J. HAMELIN, Tetrahedron Letters, 21 1397 (1967), A. VANDER WERF and R.M. KELLOGG, Tetrahedron Letters, 32 3727 (1991), E. KATO 20 et al., Chem. Pharm. Bull. 33 4836 (1985), J. ACKERMANN et al., Helv. Chim. Acta 73 122 (1990).

(XVIII) This reduction is carried out preferably The derivatives of formula (XVIII) may also be obtained by deprotection and dehydration of a derivative of formula: 18 0 or ri nh-cooc(ch3)3 cooc(ch3)3 (x x) (xix) in which R, R: and R2 have the same meanings as above or of a mixture of these derivatives. are generally carried out using trifluoroacetic acid or iodotrimethylsilane, in an inert solvent such as a chlorinated solvent (dichloromethane for example), at a temperature in the vicinity of 20°C.

The derivatives of formula (XIX) and (XX) may be obtained by action of a derivative of formula: in which R: has the same meaning as above and R:-M represents an organomagnesium or organolithium derivative or a cuprate, on a carbonyl derivative of formula: These deprotection and dehydration operations Rj-M (XXI) (XXII) cooc(ch3)3 in which R and R2 have the same meanings as above.

This reaction is carried out in an inert solvent such as tetrahydrofuran at a temperature 19 between -78 and 20°C.

The derivatives of formula (XXII) may be obtained by application or adaptation of the methods described by J. ACKERMANN et al., Helv. Chim. Acta, 73, 5 122 (1990), T. OHTA, Chem. Lett., 2091 (1987) or T. OHTA et al., Tetrahedron Letters 29 329 (1988). Preferably, ditert-butyl dicarbonate is reacted with a derivative of formula: in which R and R2 have the same meanings as above. presence of triethylamine and 4-dimethylaminopyridine in a chlorinated solvent such as dichloromethane at a temperature in the vicinity of 20°C. obtained by application or adaptation of the methods described by T. KOLASA et al., J. Org. Chem., 55, 1711 (1990), A. L. JOHNSON et al., J. Med. Chem., 28, 1596 (1985) and B. RIGO et al., J. Het. Chem., 25, 49 20 (1988), R.W. ROSENMUND and P. ENGELS, Arch. Pharm. 284 16 (1951), C.F. KOELSCH and C.H. STRATTON, J. Am. Chem. Soc. 66 1883 (1944), S. WIDEQUIST, ArK. Kemi, Mineral. Geol. 26 1 (1948), J. SINNREICH and D. ELAD, Tetrahedron Letters, 24. 4509 (1968), G.R. BROWN et al., 25 J. Chem. Soc. Chem Commun. 1973 (1984). r n h (XXIII) This reaction is generally carried out in the The derivatives of formula (XXIII) may be 24 3 5 1 4 The derivatives of formula (IV), for which R represents a methylene radical, R: represents an optionally substituted pyridyl radical, an optionally substituted quinolyl radical, an optionally substituted 5 naphthyl radical or a phenyl radical optionally substituted by one or more substituents chosen from among the halogen atoms and the alkyl, alkoxy, hydroxyl, amino, monoalkylamino, dialkylamino, alkoxycarbonyl, -CO-NR7R8 or -NH-C0-CH3 radicals, R2 10 represents an alkoxycarbonyl, cycloalkyloxycarbonyl or a cycloalkylalkyloxycarbonyl radical and R5 represents a hydrogen atom may also be obtained by reduction of a derivative of formula: in which R: and R2 have the same meanings as above. a mercury-sodium amalgam, in the presence of sodium dihydrogen phosphate or disodium hydrogen phosphate, in a solvent such as an alcohol (methanol for example), 20 tetrahydrofuran, water or a mixture of these solvents, at a temperature between -10 and 40°C, or using magnesium in an inert solvent such as an alcohol (methanol for example), at a temperature between 20°C and the boiling point of the reaction mixture.

(XXIV) h This reduction is generally carried out using 24 o * 21 The derivatives of formula (XXIV) may be obtained by action of a derivative of formula (XVI) in which Ri and R2 have the same meanings as above on phenyl vinyl sulphone.

This reaction is generally carried out in the presence of a metallic salt such as lithium bromide or silver acetate and a trialkylamine such as triethylamine in an inert solvent such as acetonitrile at a temperature in the vicinity of 20°C. 10 The derivatives of formula (IV) for which R represents a sulphur atom, R: is defined as in formula (I), R2 represents a phenyl radical and R5 represents a hydrogen atom may be obtained by action of a derivative of formula (VIII) on a 2-amino-2-phenylethanethiol, the 15 phenyl ring of which is optionally substituted by one or more substituents chosen from among the alkyl, alkoxy or hydroxyl radicals.

This reaction is generally carried out in an inert solvent such as an alcohol at the boiling point 20 of the reaction mixture.

The 2-amino-2-phenylethanethiols, the phenyl ring of which is optionally substituted, may be prepared by application or adaptation of the method described in the Patent JP 57 193 4 4 7 which makes use 25 of 2-amino-2-phenylethanols which are prepared by application or adaptation of the methods described by Z.L. KIS and J. MORLY, EP 258 191, J. PLESS, /< - CH 590 820, S. MIYAMOTO et al., EP 432 661, J. SUZUKI [' A 22 et al., EP 345 775.

The derivatives of formula (IV) for which R2 represents a phenyl optionally substituted by one or more substituents chosen from among the alkyl, alkoxy 5 or hydroxyl radicals, R represents a methylene radical, R, represents a hydrogen atom and R5 represents a phenyl radical may be prepared by application or adaptation of the methods described by W.H. PEARSON et al., J. Am. Chem. Soc. 114 1329 (1992), 0. TSUGE et al., Bull. 10 Chem. Soc. Japan 59. 2537 (1986).

These derivatives may also be prepared by reduction of the corresponding pyrroles and pyrrolines by application or adaptation of the methods described by C.G. OVERBERGER et al., J. Am. Chem. Soc. 91 687 15 (1969).

These pyrroles and these pyrrolines may be prepared by application or adaptation of the methods described by M. 0HN0 et al., Tetrahedron Letters 32. 5093 (1991), S.C. CHERKOFSKY, US 4 267 184, S.C. 20 CHERKOFSKY and G.A. BOSWELL Jr., EP 25884, 0. TSUGE et al., Bull. Chem. Soc. Japan 59. 1809 (1986).

The derivatives of formula (IV) for which R represents an ethylene radical, R2 represents a phenyl radical optionally substituted by one or more 25 substituents chosen from among the alkyl, alkoxy or hydroxyl radicals, R5 represents a hydrogen atom and R: has the same meaning as in formula (I) may be prepared by application or adaptation of the methods described ^ t R 1 r„ L> j j i 23 by C.G. OVERBERGER et al., J. Am. Chem. Soc. 7£ 6430 (1957), J. THESING and H. MEYER, Ann. 601 46 (1957), D.Y. JACKSON and P.G. SCHULTZ, J. Am. Chem. Soc. 113 2319 (1991), C.G. OVERBERGER and L.P. HERIN, J. Org.

Chem. 27 2423 (1962).

Some of these methods involve reductions of tetrahydropyridines which may also be obtained by application or adaptation of the methods described by H. QUAST and B. MUELLER Chem. Ber. 116 3931 (1983), 10 R. WEIL and N. COLLIGNON, C. Rend. Acad. Sci. Ser. C 275 299 (1972) and Bull. Soc. Chim. Fr. 258 (1974).

The derivatives of formula (IV) for which R2 represents a phenyl optionally substituted by one or more substituents chosen from among the alkyl, alkoxy 15 or hydroxyl radicals, R represents a radical CHR6, R: and R5 each represent a hydrogen atom and R6 represents a phenyl radical may be prepared by application or adaptation of the methods described by M.C. KLOEZEL, J. Am. Chem. Soc. .69 2271 ( 1947), W.H. PEARSON et al. , 20 J. Am. Chem. Soc. 114 1329 (1992), 0. TSUGE et al., Bull. Soc. Japan 59 2537 (1986), M. CARRIOU et al., Can. J. Chem. 61 2359 (1983), E. BREWER and D. MELUMAD, J. Org. Chem. 37 3949 (1972).

Some of these methods involve reductions of 25 pyrroles and pyrrolines which may also be obtained by application or adaptation of the methods described by C.F.H. ALLEN and C.V. WILSON, Org. Synth. Coll. Vol. Ill 358 (1955), W. DAVEY and D.J. TIVEY, J. Chem. Soc. 24 2276 (1958), W. CHEN et al., Chin. Chem. Lett. 2 439 (1991), S.M. BLOOM and P.P. GARCIA, US 3 883 555 and US 3 691 161.

The derivatives of formula (III) for which R2 5 represents an alkoxycarbonyl, cycloalkyloxycarbonyl or cycloalkylalkyloxycarbonyl radical may also be obtained by esterification of an acid of formula: j rRs r1 cooh (XXV) l co-ch-nh-cooc(ch3)3 in which R, R:, R4, R5 and R6 have the same meanings as 10 in formula (I).

This reaction is preferably carried out under the same conditions as those described above for the esterification of compounds of formula (V).

The acids of formula (XXV) may be obtained by 15 hydrolysis of the corresponding methyl or ethyl esters of formula (III).

This hydrolysis is generally carried out in an inert solvent such as water, dioxan or a mixture of these solvents, using a base such as an alkali metal 20 hydroxide (sodium hydroxide, potassium hydroxide) at a temperature in the vicinity of 20°C.

The derivatives of formula (III) for which R represents a methylene radical, R: represents a pyridyl radical which is optionally substituted, a quinoline radical which is optionally substituted, a naphthyl radical which is optionally substituted or a phenyl 5 radical which is optionally substituted by one or more substituents chosen from among the halogen atoms and the alkyl, alkoxy, hydroxyl, amino, monoalkylamino, dialkylamino, alkoxycarbonyl, -CO-NR7RB or -NH-CO-CH3 radicals, R2 represents an alkoxycarbonyl, 10 cycloalkyloxycarbonyl or cycloalkylalkyloxycarbonyl radical and R5 represents a hydrogen atom may be obtained by reduction of the derivatives of formula: in which Z1 represents a tert-butoxycarbonyl radical or 15 a CO-CH(R<)-NH-COOC(CH3)3 radical, R: and R2 have the same meanings as above and R* has the same meaning as in formula (I) .

This reaction is carried out under the same conditions as those described previously for the 20 reduction of the derivatives of formula (XXIV).

The derivatives of formula (XXVI) may be obtained by action of an acid of formula (V) or of di-tert-butyl dicarbonate, whichever is appropriate, on a 6 3 5 14 derivative of formula (XXIV).

This reaction is carried out in an inert solvent such as acetonitrile, tetrahydrofuran or a chlorinated solvent, in the presence of a condensation agent used in 5 peptide chemistry such as a carbodiimide (N,N'~ dicyclohexylcarbodiimide for example) or an alkyl chloroformate at a temperature between 10 and 40°C.

The optionally substituted anilines are commercially available or may be obtained by application or adaptation 10 of the methods described by R. SCHROTER, Methoden der organischen Chemie, Houben Weil, Volume XI/1, p. 360; G.J. ESSELEN et al., J. Am. Chem. Soc., 36, 322 (1914); G. ADRIANT et al., Bull. Soc. Chim. FR, 1511 (1970); W.A. JACOBS et al., J. Am. Chem. Soc., 39, 2438 (1917) and J. 15 Am. Chem. Soc., 39, 1438 (1917) and in the examples therein.

The compounds of formula (I) for which R represents a methylene, ethylene, CHOH or CHRe radical or a sulphur atom and R, represents a phenylamino radical, the phenyl 20 ring of which is optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy, alkylthio, trifluoromethyl, nitro, acyl, cyano, sulphamoyl, alkoxycarbonyl, -alk-0-alk, trifluoromethylsulphonamido, alk-SOjH, in the form of a salt, alk-COOX and alk'-COOX 25 radicals, in which X is other than a hydrogen atom, may also be prepared by action of a derivative of formula (II) on a phenyl isocyanate, the phenyl ring of which is 24 3514 £ 20 optionally substituted by one or more substituents chosen from among the halogen atoms and the alkyl, alkoxy, alkylthio, trifluoromethyl, nitro, acyl, cyano, sulphamoyl, alkoxycarbonyl, -alk-O-alk, trifluoro-methylsulphonamido, alk-SC^H, -alk-COOX or -alk'-COOX radicals, optionally in the form of a salt.

This reaction irs generally carried out in an inert solvent such as tetrahydrofuran, dimethyl-formamide, a chlorinated solvent (chloroform, 1,2-dichloroethane for example), an aromatic solvent (benzene, toluene for example) at a temperature between 10°C and the boiling point of the solvent.

The phenyl isocyanates are commercially available or may be obtained by application or adaptation of the methods described by R. RICHTER et al., The Chemistry of Cyanate and their thio derivatives, S. PATAI, part 2, Wiley New York (1977) and in the examples therein.

The compounds of formula (I) for which R represents a methylene, ethylene, CHOH or CHR« radical or a sulphur atom and R, represents a phenylamino radical, the phenyl ring of which is substituted by a carboxyl, -alk-COOH, -O-alk-COOH, -alk'-COOH, -CH=CH-COOH, -CO-COOH, -S-alk-COOH, -C(=NOH)-COOH, OCH2alk'COOH or CX=N-0-alk-C00H radical and R,, R2, R5 and R$ are defined as in formula (I) may also be prepared by hydrolysis or, where appropriate, by 28 hydrogenolysis of the corresponding esters.

When using alkyl or phenylalkyl esters, it is advantageous to carry out the hydrolysis using a base such as sodium hydroxide, potassium hydroxide or 5 lithium hydroxide in an inert solvent such as tetrahydrofuran, dioxan, water or a mixture of these solvents, at a temperature between 20°C and 40°C. When using trimethylsilylethyl ester, it is advantageous to carry out the operation in an inert solvent such as 10 tetrahydrofuran, using a fluoride such as tetrabutyl-ammonium fluoride, at a temperature between 10 and 40°C. When using phenylalkyl esters, it may also be advantageous to carry out a hydrogenolysis using hydrogen or ammonium formate in the presence of a 15 catalyst such as palladinised charcoal in a solvent such as methanol or ethyl acetate.

The trimethylsilylethyl esters may be obtained by application or adaptation of the method described in the examples.

The compounds of formula (I) for which R represents a methylene, ethylene, CHOH or CHR6 radical or a sulphur atom, R3 represents a phenylamino radical, the phenyl ring of which is optionally substituted by a hydroxyiminoalkyl or alkoxyiminoalkyl radical and Rlf 25 R2, R5 and R6 are defined as in formula (I) may also be prepared by action of the corresponding acylated derivative on a derivative of formula: H2N-OR12 (XXVII) > k 7 £ 1 /. L>; J J » in which R,2 represents a hydrogen atom or an alkyl radical.

This reaction is generally carried out in an inert solvent such as an alcohol (methanol, ethanol for example), water or a mixture of these solvents, at the boiling point 5 of the solvent and optionally in the presence of a base such as pyridine.

The compounds of formula (I) for which R represents a methylene, ethylene, CHOH or CHRf, radical or a sulphur atom and R3 represents an optionally substituted phenyl 10 radical, a naphthyl radical, an indolyl radical, an optionally substituted quinolyl radical or a phenylamino radical, the phenyl ring of which is optionally substituted r i-\ o ov" 11 o ?"* "t" c* c? »"> ^ v» Hal r\n 3 +" r\m c anH wjr wilc wjto luv^l «» vuwwwii a. •*- will 11u i. u wwillis wilu alkyl, alkoxy, alkylthio, trifluoromethyl, nitro, acyl, 15 cyano, sulphamoyl, alkoxycarbonyl, -alk-0-alk, alk-COOX and alk'-COOX radicals, in which X is other than a hydrogen atom, or trifluoromethylsulphonamido and R,, R2, R5 and ~R<, are defined as in formula (I), may also be prepared by action of a derivative of formula (IV) on an acid of 20 formula: HOOC-CH-NH-CO-Rj (XXVIII) \ I R4 in which R, has the same meaning as above or a reactive 25 derivative of this acid, and R4 has the same meaning as in formula (I).

This reaction is preferably carried out in the presence of a condensation agent used in peptide chemistry such as carbodiimide in a solvent Buch as acetonitrile, tetrahydrofuran or a chlorinated solvent or using thionyl chloride in dichloromethane at a temperature 5 between 10'c and the boiling point of the solvent.

The acids of formula (XXVIII) may be obtained by application or adaptation of the method described by J.R. JOHNSON et al., J. An. Chem. Soc., 69, 2370 (1947) or for the compounds for which R, represents a phenyl-amino 10 radical which is optionally substituted, by action of a phenyl isocyanate, the phenyl ring of which iB optionally substituted by one or more substituents chosen from among the halogen atoms and the alkyl, alkoxy, alkylthio, trifluoromethyl, nitro, acyl, cyano, sulphanoyl, 15 alkoxycarbonyl/ trifluoromethylsulphonamido, -alk-O-alk, alk-COOX or alk'-COOX radicals, in which X is other than a hydrogen atom/ on a derivative of formula: HOOC-CH-NH, (XXIX) \ R< in which has the sane meaning as in formula (I).

This reaction is generally carried out in aqueous solution in the presence of a base such as an alkali metal bicarbonate or in aqueous dioxan, at a temperature in the 25 vicinity of 20'C.

The compounds of formula (I) for which R represents an SO or S02 radical and R,, R2 and Rj are L defined as in the general formula (I) may be prepared by oxidation of the corresponding compounds of formula (I) for which R represents a sulphur atom, it being understood that the other radicals and the other substituents are chosen in 5 such a way that they are insensitive to the reaction conditions.

This oxidation is generally carried out using Oxone* (potassium peroxymonosulphate) marketed by Aldrich, in an alcohol such as methanol or a methanol-water mixture, 10 at a temperature in the vicinity of 25°C.

It will be understood by a person skilled in the art that, to implement the processes according to the invention described above, it may be necessary to introduce protecting groups of the amino, hydroxyl and carboxyl 15 functions in order to avoid secondary reactions. The amino functions may for example be blocked in the form of tert-butyl or methyl carbamates, then regenerated using iodotrimethylsilane or benzyl carbamates, then regenerated by hydrogenation after implementing the process according 20 to the invention. The hydroxyl functions may for example be blocked in the form of benzoate, then regenerated by hydrolysis in alkaline medium after implementation of the process according to the invention.

The enantiomers of the compounds of formula .43514 32 (I) , containing at least one asymmetric site, may be obtained by resolution of the racemic mixtures, for example by chiral chromatography on a chiral column or by synthesis starting from chiral precursors. phase, e.g. silica, whose chiral selector, which is, preferably, 3,5-dinitrobenzoyl-D-phenylglycine, is removed from the silica by an aminoalkyl chain, which contains 3 to 14 carbon atoms, which is fixed on the amine functions of 10 an aminopropyl silica and whose free silanol functions are blocked by trialkylsilyl radicals.

As chiral phase, it is preferable to use a This chiral phase, which constitutes another subject of the present invention, may be defined by the following structure: — 0-Si(R')3 — 0\ Si-(CH2)3-NH-CO-(CH2)n-NH-CO-CH-NH-G1 (XXX) in which the symbols R', which may be identical or different, and R", which may be identical or different, represent alkyl radicals containing 1 to 10 carbon atoms, G, represents an electro-attracting group and n represents an integer between 3 and 13 inclusive.

Preferably, one of the symbols R' represents an 5 alkyl radical containing 7 to 10 carbon atoms and the other two represent an alkyl radical containing 1 to 2 carbon atoms and preferably a methyl radical, the symbols R" are identical and represent a methyl or ethyl radical, G, represents a benzoyl radical which is optionally 10 substituted, preferably by one or more nitro radicals such as the 3,5-dinitrobenzoy1 radical, and n is equal to 10.

The new chiral phase according to the invention may be prepared by action, on an aminopropyl silica, of the anhydride of an aminoalkanoic acid which contains 3 to 14 15 carbon atoms, the amine function of which is protected by a protecting group such as the tert-butoxycarbonyl radical, followed by the blocking of a portion of the silanol functions by Si(R'), radicals as defined above, then, after elimination of the protecting group of the amine function, 20 by the amidation using D-phenylglycine, the amine function of which is protected by an electro-attracting group G, as defined above, and finally by the blocking of the residual silanol functions by Si(R")3 radicals as defined above.

Generally, the action of the aminoalkanoic acid anhydride protected on the aminopropyl silica is carried out in an anhydrous organic solvent such as dimethylformamide at a temperature in the vicinity of 20°C.

The blocking of the silanol functions by -Si(R3) groups as defined above is carried out by the action of a halogenotrialkylsilane on aminopropyl silica grafted on aminoalkanoyl residues by operating in an organic solvent such as methylene chloride in the presence of a basic agent such as pyridine.

The elimination of the protecting groups of the aminoalkanoyl residues is generally carried out, when the protecting group is a tert-butoxycarbonyl radical, by the action of trifluoroacetic acid in an organic solvent such as methylene chloride.

The amidation using D-phenylglycine, the amine function of which is protected, is carried out in the presence of a condensation agent such as N-ethoxy-carbonyl-2-ethoxy-l,2-dihydroquinoline by operating in an anhydrous organic solvent such as dimethylformamide.

The blocking of the residual silanol functions by -Si(RM)3 radicals as defined above is generally carried out using trialkylsilylimidazole in an organic solvent such as methylene chloride.

The compounds of formula (I) may be purified by , 3 5 the usual known methods, for example by crystallisation, chromatography or extraction.

The compounds of formula (I) may optionally be converted into addition salts with a mineral or organic 5 acid by the action of such an acid in an organic solvent such as an alcohol, a ketone, an ether or a chlorinated solvent.

The compounds of formula (I) having a carboxyl, sulpho or alk-SOjH residue may also be converted into 10 metallic salts or into addition salts with nitrogen- containing bases by methods known per se. These salts may be obtained by the action of a metallic base (alkali metal or alkaline earth metal for example), of ammonia, of an amine or of a salt of an organic acid on a compound of 15 formula (I) in a solvent. The salt formed is separated by the usual methods.

These salts also form part of the invention.

The addition salts with inorganic or organic acids (such as acetate, propionate, succinate, benzoate, 20 fumarate, maleate, oxalate, methanesulphonate, isethionate theophyllinacetate, salicylate, methylene-bis-0-oxynaphthoate, hydrochloride, sulphate, nitrate and phosphate), the salts with alkali metals (sodium, potassium, lithium) or with alkaline earth metals (calcium, magnesium), the ammonium salts, the salts of nitrogen-containing bases (ethanolamine, trimethylamine, methylamine, benzylamine, N-benzyl-/3-phenethylamine, 5 choline, arginine, leucine, lysine, N-methylglucamine) may be cited as examples of pharmaceutically acceptable salts.

The compounds of formula (I) have advantageous pharmacological properties. These compounds possess a strong affinity for the receptors of cholecystokinin (CCK) 10 and of gastrin and are therefore useful in the treatment and the prevention of the disorders linked to CCK and to gastrin at the level of the nervous system and of the gastrointestinal apparatus.

It thus follows that these compounds may be 15 used for the treatment or the prevention of psychoses, of anxiety disorders, of Parkinson's Disease, of tardive dyskinesia, of the irritable colon syndrome, of acute pancreatitis, of ulcers, of intestinal motility disorders, of certain tumours sensitive to CCK and as appetite 20 regulators.

These compounds also have a potentiating effect on analgesic activity of narcotic and nonnarcotic medicaments. Moreover, they may have an inherent analgesic effect.

Since the compounds have strong affinity for the CCK receptors, they furthermore modify the capacity for memory. As a consequence, these compounds may be effective for memory disorders.

The affinity of compounds of formula (I) for the CCK receptors has been determined by a technique inspired from that of A. SAITO et al., (J. Neuro. Chem., 37, 483-490 (1981)) at the level of the cerebral cortex and at the level of the pancreas.

In those tests, the IC50 of the compounds of formula (I) is generally smaller than or equal to 1000 nM.

It is furthermore known that the products which recognise the central CCK receptors have a similar specificity for the gastrin receptors in the gastrointestinal tract (BOCK et al., J. Med. Chem., 32, 16-23 (1989); REYFELD et al., Am. J. Physiol., 240, G255-266 (1981); BEINFELD et al., Neuropeptides, 3, 411-427 (1983)).

The compounds of formula (I) have a low toxicity. Their LDS0 is generally greater than 40 mg/kg when administered subcutaneously in mice.

Of particular interest are the compounds of formula (I) for which R represents a methylene radical, a sulphur atom or an SO radical, R, represents a phenyl radical which is optionally substituted, R2 represents a 24 35 1 ^ phenyl or alkoxycarbonyl radical, R, and R5 represent a hydrogen atom, R3 represents a phenylamino radical, the phenyl ring of which is substituted by a carboxyl, -alk-COOH, -S-alk-COOH, hydroxyalkyl, -alk'-COOH, -alkS03' 5 or hydroxyiminoalkyl radical. More particularly interesting are the products of formula (I) in which Rj and R2 are in the cis position with respect to one another.

Of particular interest are the following compounds: - tert-butyl (2RS,5SR)-l-{2-[3-(3-((RS)hydroxyethyl)-phenyl)ureido]acetyl}-5-phenylprolinate, - 2-{3-{3-[2-((2S,5R)-2-tert-butoxycarbony1-5-phenyl-l-pyrrolidinyl) -2-oxoethyl]ureido}pheny1>propionic acid (B form), - (2RS,5SR)-{3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}phenylthio}acetic acid, —(2R,4R)-3-{3-[2-(4-tert-butoxycarbonyl-2-(2-fluoro-3-thiazolidinyl))-2-oxoethyl]ureido}phenylacetic acid, - 2-{3-{3-[2-((2R,4R)-2-tert-butoxycarbony1-2-(2-fluoro- phenyl)-3-thiazolidinyl)-2-oxoethyl]ureido}phenyl}propionic acid (B form), - potassium (RS)-l-{3-{3-[2-((2R,4R)-4-tert-butoxy-carbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido}-phenyl}ethanesulphonate, mixture of A and B forms, - potassium (RS)-l-{3-{3-[2-((2S,5R)-2-tert-butoxycarbony 1-5-phenyl-l-pyrrolidinyl) -2-oxoethyl] ureido}- 4 j >j 7 n -i .j i phenyl}ethanesulphonate, - potassium (2S,5R)-l-{3-{3-[2-2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}phenyl}-methanesulphonate, - (2S,5R)-3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}benzoic acid, - (2RS,5SR)-3-{3-{2-[2-tert-butoxycarbonyl-5-(2- fluorophenyl)-1-pyrrolidiny1]-2-oxoethyl}ureido}benzoic acid, - cis-3-{3-[2-(2,5-diphenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}benzoic acid, - (2RS,5SR)-3-{2-[2-(2-hydroxyphenyl)-5-phenyl-l-pyrrolidinyl]-2-oxoureido}pher.ylacetic acid, - (2R,4R)-3-{3-[2-(4-tert-butoxycarbonyl-2-phenyl-3-15 thiazolidinyl)-2-oxoethyl]ureido}phenylacetic acid, - (2R,4R)-3-{3-[2-(4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido}benzoic acid, - 2—{3—{3—[2—((IRS,2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-l-oxide-3-thiazolidinyl)-2-oxoethyl]- ureido}phenyl}propionic acid (A form) , - (2R,4R)-3-{3-[2-(4-tert-butoxycarbonyl-2-(2 , 3-di-fluorophenyl)-3-thiazolidinyl)-2-oxoethyl]ureido}-phenylacetic acid, and - tert-butyl (2RS,5SR)-l-{2-{3-[(E)-3-(1-hydroxyimino-2 5 ethyl)phenyl]ureido}acetyl}-5-phenylprolinate.

The following examples illustrate the invention.

J J 40 Example 1 Sulphinyl chloride (0.9 cc) is added slowly to a suspension of tert-butyl (2RS,5SR)-5-phenylprolinate (3.1 g) and of 2-[3-(3-methyl-5 phenyl)ureido]acetic acid (2.6 g) in anhydrous 1,2-dichloroethane (100 cc) heated to reflux. The reaction mixture is then heated under reflux for 15 minutes, then cooled to 50cC and neutralised to a pH of 7-8 by addition of a 10 % aqueous sodium bicarbonate solution. 10 The organic phase is washed with water (3 x 50 cc), dried over magnesium sulphate, filtered and concentrated to dryness under reduced pressure. The crude product obtained is purified by chromatography on silica [eluent: dichloromethane/methanol (98/2 by 15 volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at a temperature in the vicinity of 45°C.

After recrystallisation in acetonitrile, tert-butyl (2RS,5SR)-1-{2-[3-(3-methylphenyl)ureido]acetyl}-5-20 phenylprolinate (1 g), m.p. 156°C, is obtained.

A - 2-[3-(3-Methylphenyl)ureido]acetic acid may be prepared as follows: 3-methylphenyl isocyanate (53.2 g) is added in the space of 15 minutes to a solution of glycine (30 g) and of sodium bicarbonate (53 g) in 25 water (600 cc). The reaction mixture is stirred for 4 hours at a temperature in the vicinity of 25°C, then washed with ethyl acetate (200 cc) and acidified to a 243514 41 pH of 1 with a 4N aqueous hydrochloric acid solution (200 cc). The insoluble product is separated by filtration, washed with water (3 x 80 cc) and dried in air. 2-[3-(3-Methylphenyl)ureido]acetic acid (72 g), 5 m.p. 208°C, is thus obtained.

B - tert-Butyl (2RS,5SR)-5-phenylprolinate may be prepared as follows: a suspension of (2RS,5SR)-5-phenylproline hydrochloride (45 g) in anhydrous chloroform (500 cc) is stirred and cooled to a 10 temperature in the vicinity of 5°C. Concentrated sulphuric acid (5.5 cc) is added dropwise, and the reaction mixture is saturated with isobutene for 2 hours while stirring and maintaining the temperature at 5°C. After returning to a temperature in the vicinity 15 of 20°C, stirring is continued for 20 hours. The reaction mixture is then brought to a pH of 8 with a 4N aqueous sodium hydroxide solution. The organic phase is decanted, washed with water (3 x 100 cc), dried over magnesium sulphate and concentrated to dryness under 20 reduced pressure at a temperature in the vicinity of 40°C. tert-Butyl (2RS,5SR)-5-phenylprolinate (40 g) is obtained in the form of an orange oil, used as it is in subsequent syntheses. (2RS,5SR)-5-phenylproline hydrochloride may 25 be prepared according to the method described by H. GERSHON and A. SCALA, J. Org. Chem., 25, 2347-50 (1961) . 42 Example 2 3-Methoxyphenyl isocyanate (0.9 cc) is added to a solution of tert-butyl (2RS,5SR)-l-(2-aminoacetyl)-5-phenylprolinate (2 g) in anhydrous 5 tetrahydrofuran (20 cc). The reaction mixture is stirred for 20 hours at a temperature in the vicinity of 25°C. After evaporation of the solvent under reduced pressure at a temperature in the vicinity of 45°C, the crude product obtained is purified by chromatography on 10 silica [eluent: dichloromethane/methanol (95/5 by volume)]. The fractions containing the expected product are combined, then concentrated to dryness under reduced pressure. After recrvstallisation in acetonitrile, tert-butyl (2RS,5SR)-l-{2-[3-(3-15 methoxyphenyl)ureido]acetyl}-5-phenylprolinate (1.9 g), m.p. 174°C, is obtained.

A - tert-Butyl (2RS,5SR)-l-(2-aminoacetyl)-5-phenylprolinate may be prepared as follows: at a temperature in the vicinity of 25#C iodotrimethylsilane 20 (5.6 cc) is added dropwise to a solution of tert-butyl (2RS,5SR)-1-(2-tert-butoxycarbonylaminoacetyl)-5-phenyl-prolinate (16 g) in chloroform (150 cc). The reaction mixture is stirred for 20 hours at this temperature, then concentrated to dryness under reduced 25 pressure at a temperature in the vicinity of 45°C. The crude product obtained is purified by chromatography on silica [eluent: dichloromethane/methanol (90/10 by 43 volume)]. The fractions containing the expected product are combined and then concentrated to dryness under reduced pressure. tert-Butyl (2RS,5SR)-l-(2-aminoacetyl)-5-phenylprolinate (10 g) is thus obtained 5 in the form of an amorphous white product, used as it is in subsequent syntheses.

Proton NMR (250 MHz, DMSO D6, S in ppm), 2 rotamers at room temperature, 1.5 (s, 9H, C(CH3)3, 1.8 to 2.4 (bm, 4H, CH2-CH2); 2.7, 3.25, 3.45 and 3.6 (bd, 2H, AB, 10 CH2C02) ; 4.3 (bt, 1H, CHN); 5.05 (bm, 1H, CHN); 7.2 to 7.8 (m, 5H, aromatic).

B - tert-Butyl (2RS,5SR)-1-(2-tert-butoxycarbonylamino-acetyl)-5-phenylprolinate may be prepared as follows: in the space of 30 minutes a solution of N,N'-dicyclo-15 hexylcarbodiimide (9.6 g) in anhydrous acetonitrile (50 cc) is added to a solution of tert-butyl (2RS,5SR)-5-phenylprolinate (11.5 g) and of 2-tert-butoxycarbonylaminoacetic acid (8.2 g) in anhydrous acetonitrile (150 cc) kept at a temperature in the 20 vicinity of 0°C. The reaction mixture is stirred for 16 hours at a temperature in the vicinity of 25°C, then the insoluble product is separated by filtration and washed with dichloromethane (3 x 30 cc). The filtrate is concentrated to dryness under reduced pressure at a 25 temperature in the vicinity of 45°C. After recrystallisation in pentane, tert-butyl (2RS,5SR)-1-(2-tert-butoxycarbonylamino-acetyl)-5-phenylprolinate 44 (16 g), m.p. 112°C, is obtained.

Example 3 A solution of tert-butyl (2RS,5SR)-l-(2-aminoacetyl)-5-phenylprolinate (3.1 g) in anhydrous 5 1,2-dichloroethane (50 cc) is slowly added to a solution of N,N'-diimidazole-carbonyl (1.8 g) in anhydrous 1,2-dichloroethane (50 cc). The reaction mixture is stirred for 1 hour at a temperature in the vicinity of 25°C, followed by the addition of (RS)-l-10 (3-aminophenyl)ethanol (1.4 g). The reaction mixture is then heated under reflux while stirring for 4 hours. After cooling, the mixture is washed with water (3 x 50 cc); the organic phase is dried over magnesium sulphate and the solvent is evaporated to dryness under 15 reduced pressure at a temperature of 45°C. The oily residue obtained is purified by chromatography on silica [eluent: dichloromethane/methanol (95/5 by volume)] and the fractions containing the expected product are combined and then concentrated to dryness 20 under reduced pressure. After recrystallisation in acetonitrile, tert-butyl (2RS,5SR)-l-{2-[3-(3-(RS)-l-hydroxyethyl)phenyl)ureido]acetyl}-5-phenylprolinate (1.8 g), m.p. 1608C, is obtained.

Example 4 By proceeding in a fashion similar to that described in Example 3, but starting from N,N'- 24 35 14 45 diimidazole-carbonyl (1.8 g), tert-butyl (2RS,5SR)-1-(2-aminoacetyl)-5-phenylprolinate (3.1 g) in solution in anhydrous 1,2-dichloroethane (100 cc) and 3-methyl-thioaniline (1.3 cc), after recrystallisation in 5 acetonitrile, tert-butyl (2RS,5SR)-l-{2-[3-(3- methylthiophenyl)ureido]acetyl}-5-phenylprolinate (1.8 g), m.p. 163°C, is obtained.

Example 5 By proceeding in a fashion similar to that 10 described in Example 3, but starting from N,N'-di- imidazole-carbonyl (1.8 g), tert-butyl (2RS,5SR)-l-(2-aminoacetyl)-5-phenylprolinate (3-1 g) in solution in anhydrous 1,2-dichloroethane (100 cc) and 3-aminophenylmethanol (1.25 g), after recrystallisation 15 in acetonitrile, tert-butyl (2RS,5SR)-l-{2-[3-(3- hydroxymethylphenyl)-ureido]acetyl}-5-phenylprolinate (1.8 g), m.p. 168°C, is obtained.

Example 6 By proceeding in a fashion similar to that 20 described in Example 3, but starting from N,N'-di- imidazole-carbonyl (1.8 g), tert-butyl (2RS,5SR)-l-(2-aminoacetyl)-5-phenylprolinate (3.1 g) in solution in anhydrous 1,2-dichloroethane (100 cc) and 3-amino-acetophenone (1.5 g), after recrystallisation in a 25 cyclohexane-methanol (9/1 by volume) mixture, tert- butyl ( 2RS,5SR)-1-{2-[3-(3-acetylphenyl)ureido]acetyl}- £=r„ 46 -phenylprolinate (1.1 g), m.p. 122°C, is obtained. Example 7 Hydroxylamine hydrochloride (0.5 g) in solution in water (6 cc) is added to a solution of 5 tert-butyl (2RS,5SR)-l-{2-[3-(3-acetylphenyl)- ureido]acetyl}-5-phenylprolinate (3 g) in methanol (12 cc) and pyridine (6 cc). The reaction mixture is heated under reflux for 2 hours. After evaporation of the solvents under reduced pressure at a temperature in 10 the vicinity of 45 °C, the residue is taken up in ethyl acetate (100 cc) and the organic phase is washed with (3 x 50 cc) f dried ovsr iric»QTi6si.ujn sulphists, filtered and concentrated to dryness under reduced pressure. The crude product obtained is purified by 15 chromatography on silica [eluent: dichloromethane/methanol (95/5 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at a temperature in the vicinity of 40°C. After 20 recrystallisation in acetonitrile, tert-butyl (E)-(2RS,5SR)-l-{2-{3-[3-(1-hydroxyiminoethyl)phenyl]-ureido}acetyl}-5-phenylprolinate (1.1 g), m.p. 118°C, is obtained. 47 Example 8 By proceeding in a fashion similar to that described in Example 3, but starting from N,N'-di-imidazole-carbonyl (12.5 g), (2RS,5SR)-l-(2-5 aminoacetyl)-5-phenylprolinate (21.3 g) in solution in anhydrous 1,2-dichloroethane (400 cc) and ethyl 3-aminobenzoate (10.5 cc), tert-butyl (2RS,5SR)-l-{2-[3-(3-ethoxycarbonylphenyl)ureido]acetyl}-5-phenylprolinate (24.8 g) is obtained in the form of a 10 meringue-like white product [proton NMR (250 MHz, DMSO D6, 6 in ppm),2 rotamers at room temperature, peak coalescence at 120°C, general description valid for the other products of the series: 1.35 (t, 3H, ethyl CH3); 1.50 (bs, 9H, (CH3)3); 1.90 to 2.5 (m, 4H, H in position 15 3 and 4 on pyrrolidine); 3.9 and 3.5 (ABX, 2H, CH2N) ; 4.3 (q, 2H, CH20); 4.5 (vbdd, 1H, H in position 2 on pyrrolidine); 5.15 (dd, 1H, H in position 5 on pyrrolidine); 6.2 (bdd, 1H, NH); 7.2 to 7.6 (m, 8H, aromatic); 8 (bs, 1H, H in position 2 on urea phenyl); 20 8.7 (bs, 1H, NH).

Infrared spectrum (KBr), characteristic bands in cm'1: 3375, 3150, 3090, 3065, 3030, 2980, 2930, 2870, 1720, 1635, 1610, 1595, 1555, 1490, 1450, 1430, 1390, 1365, 1300, 1285, 1235, 1180, 1150, 1105, 1030, 860, 840, 25 755, 700, 685].

Example 9 Potassium hydroxide (0.9 g) dissolved in 2 4 3 5 14 48 distilled water (60 cc) is added to a solution of tert-butyl (2RS,5SR)-l-{2-[3-(3-ethoxycarbonylphenyl) ureido]acetyl}-5-phenylprolinate (8 g) in methanol (120 cc). The reaction mixture is stirred for 5 3 hours at a temperature in the vicinity of 25°C, then concentrated to 50 cc under reduced pressure. The solution obtained is diluted with water (30 cc), washed with ethyl acetate (2 x 50 cc), acidified to a pH of 2 with a 4N aqueous hydrochloric acid solution and 10 extracted with dichloromethane (3 x 100 cc). The organic phases are combined, washed with water (2 x 50 cc), dried over magnesium sulphate and concentrated to dryness under reduced pressure at a temperature in the vicinity of 40°C. The crude product 15 obtained is purified by chromatography on silica [eluent: dichloromethane/methanol (90/10 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure. After recrystallisation in ethyl acetate, 20 (2RS,5SR)-3-{3-[2-(2-tert-butyoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}benzoic acid (4.5 g), m.p. 236°C, is obtained.

Example 10 By proceeding in a fashion similar to that 25 described in Example 3, but starting from N,N'- diimidazole-carbonyl (1.8 g), tert-butyl (2RS,5SR)-1-(2-aminoacetyl)-5-phenylprolinate (3.1 g) in solution 49 in anhydrous 1,2-dichloroethane (100 cc) and 2-(3-amino-phenyl)ethanol (1.4 g), after recrystallisation in acetonitrile, tert-butyl (2RS,5SR)-l-({2-{3-[3-(2-hydroxyethyl)phenyl]ureido > acetyl}-5-phenylprolinate 5 (1.5 g), m.p. 162°C, is obtained.

A - 2-(3-Aminophenyl)ethanol may be prepared as follows: palladinised charcoal (0.75 g/5 %) is added to a solution of 2-(3-nitrophenyl)ethanol (15 g) in ethanol (250 cc). The slurry is stirred for 2 hours at 10 a temperature in the vicinity of 25°C under a hydrogen atmosphere (130 kPa). The catalyst is separated by filtration and the filtrate is concentrated to dryness -i 4- A C. 0 n O / O unuci. j.cuuucu ^/xcooui.c au ** j"niuxiiw phenyl)ethanol (12 g) is thus obtained in the form of 15 an orange oil, used as it is in subsequent syntheses.

Example 11 By proceeding in a fashion similar to that described in Example 3, but starting from N,N'-carbonyldiimidazole (3.6 g), tert-butyl (2RS,5SR)-l-(2-20 aminoacetyl)-5-phenylprolinate (6.2 g) in solution in anhydrous 1,2-dichloroethane (150 cc) and ethyl (E)-3-aminocinnamate (3.9 g), ethyl (E)-3-{3-[2-((2RS,5SR)-2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}cinnamate (4.8 g) is obtained [proton 25 NMR (250 MHz, DMSO D6, 6 in ppm, J in Hz), 2 rotamers at room temperature, peak coalescence at 120°C: 1.3 (t, 24 3 5 7 50 3H, CH3); 1.5 (bs, 9H, (CH3)3); 4.25 (q, 2H, CH20); 6.4 (d, 1H, J=15, CH= trans); 7.10 to 7.70 (m, 10H, aromatic and CH= trans). Infrared spectrum (KBr), characteristic bands in cm"1: 3375, 3150, 3070, 3035, 5 2980, 2940, 2880, 1740, 1700, 1640, 1610, 1590, 1560, 1495, 1490, 1455, 1430, 1395, 1370, 1310, 1270, 1220, 1180, 1160, 1040, 990, 860, 840, 790, 760, 705, 685].

Ethyl (E)-3-aminocinnamate may be prepared according to the method described in the Patent Application NL 7416449 (corresponding to GB 1431640) (C.A. 84,58882q).

Example 12 By proceeding in a fashion similar to that described in Example 9, but starting from ethyl (E)—3— {3-[2-((2RS,5SR)-2-tert-butoxycarbonyl-5-phenyl-l-15 pyrrolidinyl)-2-oxoethyl]ureido}cinnamate (3.7 g) in solution in methanol (60 cc) and potassium hydroxide (0.4 g) dissolved in water (20 cc) and after treatment, (E)-3-{3-[2-((2RS, 5SR)-2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureidoycinnamic acid (1 g) 20 is obtained [proton NMR (250 MHz, DMSO D6, S in ppm, J in Hz), 2 rotamers at room temperature, preponderant rotamer description, general description valid for the other products of the series: 1.5 (bs, 9H, (CH3)3; 1.9 and 2.2 (2m, 4H, H in position 3 and 4 on pyrrolidine); 25 3.2 and 3.9 (ABX, 2H, CH2N); 4.35 (dd, 1H, H in position 2 on pyrrolidine); 5.20 (dd, 1H, H in position^-5 on pyrrolidine); 6.30 (dd, 1H, NH); 6.4 (bd, 1H, r* / -■ f -j ff L -f I 51 J=15, CH= trans); 7.1 to 7.7 (m, 10H, aromatic and CH= trans); (s, 1H, NH). Infrared spectrum (KBr), characteristic bands in cm"1: 3380, 3075, 3030, 3700 to 2250 with a maximum at 2475, 2980, 2935, 2875, 1735, 5 1705, 1695, 1640, 1610, 1590, 1560, 1495, 1450, 1430, 1395, 1370, 1315, 1250, 1225, 1155, 985, 910, 890, 860, 840, 790, 760, 705, 685].

Example 13 By proceeding in a fashion similar to that 10 described in Example 3, but starting from N,N' - carbonyldiimidazole (3.6 g), tert-butyl (2RS,5SR)-1-(2-aminoacetyl)-5-phenylprolinate (6.2 g) in solution in anhydrous 1,2-dichloroethane (125 cc) and ethyl 3-(3-aminophenyl)propionate (3.9 g), after crystallisation 15 in a mixture of pentane/isopropanol (60/40 by volume), ethyl (2RS,5SR)-3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}-3-phenylpropionate (5.3 g), m.p. 96°C, is obtained.

Ethyl 3-(3-aminophenyl)propionate may be 20 prepared in a fashion similar to that described in Example 10 §A, but starting from ethyl (E)-3-nitrocinnamate (16.8 g) in solution in ethanol (500 cc) and palladinised charcoal (0.9 g/5 %). Ethyl 3-(3-amino-phenyl)propionate (14.2 g) is thus obtained in 25 the form of an oil, used as it is in subsequent syntheses.

Ethyl (E)-3-nitrocinnamate may be prepared as 52 follows: pure sulphuric acid (5 cc) is added to a solution of (E)-3-nitrocinnamic acid (31 g) in ethanol (300 cc). The reaction mixture is stirred under reflux for 3 hours. After cooling and addition of water 5 (50 cc), the solution is concentrated to about 60 cc under reduced pressure at 40°C. Ethyl acetate (250 cc) is added, the organic phase is then washed successively with a 12N aqueous sodium hydroxide solution (2 x 100 cc), with water (2 x 100 cc), then dried over 10 magnesium sulphate and concentrated to dryness under reduced pressure at 4 0°C. Ethyl (E)-3-nitrocinnamate (32 g), m.p. 70°C, is thus obtained.

(E)-3-Nitrocinnamic acid may be prepared as follows: a mixture of 3-nitrobenzaldehyde (30.2 g), of 15 malonic acid (20.8 g), of pyridine (15.8 g) and of piperidine (0.15 cc) is heated under reflux for 1 hour. After cooling, water (50 cc) is added and the insoluble product is separated by filtration, washed with water (3 x 50 cc) and dried in the air. (E)— 3— 20 Nitrocinnamic acid (31 g), m.p. 205°C, is thus obtained.

Example 14 By proceeding in a fashion similar to that deescribed in Example 9, but starting from ethyl 25 (2RS,5SR)-3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}-3-phenylpropionate (3.9 g) in solution in methanol (60 cc) and potassium 53 hydroxide (0.45 g) dissolved in water (20 cc) and after treatment, (2RS,5SR)-3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-1-pyrrolidinyl)-2-oxoethy1]ureido} - 3 -phenylpropionic acid is obtained [proton NMR (250 MHz, 5 DMSO D6, 5 in ppm), 2 rotamers at room temperature, peak coalescence at 120°C; 15. (bs, 9H, (CH3)3); 2.5 (t, 2H, CH2); 2.8 (t, 2H, CH2); 6.8 to 7.60 (m, 9H, aromatic). Infrared spectrum (KBr), characteristic bands in cm"1: 3380, 3700 to 2250 with a maximum at 2625, 3160, 3060, 10 3030, 2980, 2930, 2880, 1735, 1635, 1610, 1595, 1560, 1495, 1450, 1440, 1395, 1370, 1310, 1225, 1155, 905, 890, 865, 840, 790, 760, 705].

Example 15 By proceeding in a fashion similar to that 15 described in Example 3, but starting from N,N' - carbonyldimiidazole (2.9 g), tert-butyl (2RS,5SR)-l-(2-aminoacetyl)-5-phenylprolinate (5 g) in solution in anhydrous 1,2-dichloroethane (100 cc) and ethyl 3-aminophenoxypropionate (3.2 g), ethyl (2RS,5SR)-3-{3-20 [2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}phenoxyacetate (4.9 g) is obtained [proton NMR (200 MHz,, DMSO D6, 6 in ppm), 2 rotamers at room temperature, preponderant rotamer description: 1.15 (bt, 3H, ethyl CH3); 1.50 (bs, 9H, (CH3)3); 4.2 (q, 25 2H, ethyl CH2); 4.5 (bs, 2H, 0CH2C0); 6.4 (bd, 1H, H in position 6 on urea phenyl); 6.8 to 7.75 (m, 8H, aromatic). Infrared spectrum (KBr), characteristic ■ 1 — f 54 bands in cm"1: 3375, 3150, 3090, 3060, 3030, 2980, 2930, 2930, 2875, 1758, 1735, 1700, 1638, 1600, 1550, 1495, 1450, 1430, 1390, 1365, 1295, 1220, 1190, 1155, 1085, 1030, 860, 840, 760, 700, 690].

Ethyl 3-aminophenoxyacetate may be prepared as described in Example 10 §A, but starting from ethyl 3-nitrophenoxyacetate (18 g) in solution in ethanol (250cc) and palladinised charcoal (0.2 g/5 %). Ethyl 3-aminophenoxyacetate (15 g) is thus obtained in the 10 form of an oil, used as it is in subsequent syntheses.

Ethyl 3-nitrophenoxyacetate may be prepared as follows: in the space of 20 minutes, an oily suspension (50 % by weight) (4,8 g) of sodium hydride is added to a solution of 3-nitrophenol (13.9 g) in 15 anhydrous dimethylformamide (125 cc). The mixture obtained is stirred at a temperature in the vicinity of 25°C for 30 minutes, then, in the space of 10 minutes, ethyl chloroacetate (10.8 cc) is added. The reaction mixture is stirred for 20 hours at a temperature in the 20 vicinity of 20°C, then poured into water (400 cc) and extracted with ethyl acetate (3 x 200 cc). The combined organic phases are dried over magnesium sulphate and concentrated to dryness under reduced pressure at a temperature of 35°C. Ethyl 3-nitrophenoxyacetate (18 g) 25 is obtained in the form of an orange oil, used as it is in subsequent syntheses. } 5 1 4 55 Example 16 By proceeding in a fashion similar to that described in Example 9, but starting from ethyl (2RS,5SR)-3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-1-5 pyrrolidinyl)-2-oxoethyl]ureidoJphenoxyacetate (3.7 g) in solution in methanol (80 cc) and potassium hydroxide (0.4 g) dissolved in water (40 cc), after treatment and recrystallisation in isopropyl acetate, (2RS,5SR)-3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-10 oxoethyl]ureido>phenoxyacetic acid (1.4 g), m.p. 192°C, is obtained.

Example 17 By proceeding in a fashion similar to that described in Example 3, but starting from N,N'-15 carbonyldiimidazole (3.6 g), tert-butyl (2RS,5SR)-l-(2-aminoacetyl)-5-phenylprolinate (6.2 g) in solution in anhydrous 1,2-dichloroethane (150 cc) and ethyl 3-(aminophenylthio)acetate, ethyl (2RS,5SR)-{3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-20 oxoethyl]ureido}phenylthio}acetate (4.9 g) is obtained [proton NMR (300 MHz, DMSO D6, S in ppm), 2 rotamers at room temperature, preponderant rotamer description: 1.2 (t, 3H, ethyl CH3); 1.5 (bs, 9H, (CH3)3); 3.8 (bs, 2H, CH2S); 4.2 (q, 2H, ethyl CH20); 6.9 to 7.7 (m, 9H, 25 aromatic). Infrared spectrum (KBr), characteristic bands in cm'1: 3365, 3130, 3085, 3065, 3030, 2980, 2930, 56 2875, 1735, 1700, 1635, 1585, 1545, 1480, 1498, 1425, 1450, 1395, 1365, 1305, 1295, 1275, 1220, 1150, 1030, 885, 865, 840, 780, 760, 700, 690].

Ethyl (3-aminophenylthio)acetate may be 5 prepared as follows: in the space of 5 minutes, ethyl bromoacetate (16.7 g) is added to a solution of 3-aminothiophenol (12.5 g) in ethanol (200 cc). The mixture is stirred at a temperature in the vicinity of 20°C for 3 hours, then concentrated to dryness under 10 reduced pressure at 40°C. The product obtained is dissolved in ethyl acetate (100 cc) and washed in a IN -aqueous sodium hydroxide solution (100 cc). The organic phase is separated, washed with water (2 x 50 cc), t dried over magnesium sulphate and concentrated to 15 dryness under reduced pressure. The product obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (70/30 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C.

Ethyl (3-aminophenylthio)acetate (13 g) is thus obtained in the form of an oil, used as it is in subsequent syntheses.

Example 18 By proceeding in a fashion similar to that 25 described in Example 9, but starting from ethyl (2RS,5SR)-{3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l- 2 4 3 5 14 pyrrolidinyl)-2-oxoethyl]ureido>phenylthio}acetate (4 g) in solution in methanol (80 cc) and potassium hydroxide (0.45 g) dissolved in water (40 cc) and after treatment and crystallisation in an isopropyl ether/isopropyl acetate 5 mixture (50/50 by volume), (2RS,5SR)-{3-{3-[2-(2-tert-butoxycarbony 1-5-phenyl-l-pyrrolidinyl) -2-oxoethyl]ureido}phenylthio}acetic acid (2 g), m.p. 136°C, is obtained.

Example 19 By proceeding in a fashion similar to that described in Example 3, but starting from N,N'-carbonyldimiidazole (3.6 g), tert-butyl (2RS,5SR)-l-(2-aminoacetyl)-5-phenylprolinate (6.2 g) in solution in anhydrous 1,2-dichloroethane (150 cc) and ethyl 5-aminosalicylate 15 (3.7 g), ethyl (2RS,5SR)-5-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido)salicylate (3.1 g), m.p. 150°C, is obtained.

Ethyl 5-aminosalicylate may be prepared in a fashion similar to that described in Example 10 §A, but starting 20 from ethyl 5-nitrosalicylate (10 g) in solution in ethanol (200 cc) and palladized charcoal (0.5 g/5 %). Ethyl 5-aminosalicylate (8.5 g) is thus obtained in the form of an orange oil, used as it is in subsequent syntheses. 58 Ethyl 5-nitrosalicylate may be prepared as follows: concentrated sulphuric acid (3 cc) is added to a solution of 5-nitrosalicylic acid (10 g) in ethanol (250 cc). The reaction mixture is stirred to reflux for 5 70 hours. After cooling and addition of water (50 cc), the solution is concentrated to about (60 cc) under reduced pressure at 40°C. Ethyl acetate (250 cc) is added, the organic phase is then washed with distilled water (2 x 100 cc), dried over magnesium sulphate and 10 concentrated to dryness under reduced pressure. The crude product obtained is purified by chromatography on-silica [eluent: dichloromethane]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 15 40°C. Ethyl 5-nitro-salicylate (10 g), m.p. 97°C, is thus obtained.

Example 20 By proceeding in a fashion similar to that described in Example 9, but starting from ethyl 20 (2RS, 5SR)-5-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l~ pyrrolidinyl)-2-oxoethyl] ureido} salicylate (4.7 g) in solution in methanol (80 cc) and potassium hydroxide (1.04 g) dissolved in water (40 cc) and after treatment, (2RS,5SR)-5-{3-[2-(2-tert-butoxycarbonyl-5-25 phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}salicylic acid (2.3 g), m.p. 190°C, is obtained. 59 Example 21 By proceeding in a fashion similar to that described in Example 2, but starting from tert-butyl (2RS,5SR)-l-(2-aminoacetyl)-5-phenylprolinate (6.2 g) 5 in solution in anhydrous tetrahydrofuran (150 cc) and methyl 3-isocyanatophenylacetate (4.2 g), methyl (2RS,5SR)-3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}phenylacetate (6 g) is obtained [proton NMR (200 MHz, DMSO D6/ S in ppm), 2 10 rotamers at room temperature, peak coalescence at 120 °C: 1.5 (s, 9H, (CH3)3); 3.6 (s, 2H, CH2C0); 3.65 (s, 3H, OCH3);6.8 to 7.7 (m, 9H, aromatic). Infrared spectrum (KBr), characteristic bands in cm"1: 3365, 3155, 3110, 3090, 3060, 3030, 2975, 2950, 2930, 2875, 15 1738, 1700, 1650, 1610, 1595, 1560, 1495, 1435, 1395, 1365, 1315, 1250, 1220, 1155, 1015, 905, 890, 860, 845, 780, 760, 700].

Methyl 3-isocyanatophenylacetate is prepared as follows: at a temperature in the vicinity of -20°C 20 and under argon, methyl 3-aminophenylacetate (8.25 g) in solution in toluene (100 cc) is added to a suspension of charcoal (1 g) and diphosgene (6 cc) in toluene (70 cc). The reaction mixture is stirred and maintained at -20#C for 15 minutes, then, after 25 returning to a temperature in the vicinity of 20°C, heated under reflux for 2 hours and 30 minutes. The mixture is then degassed by bubbling through argon for 30 minutes, filtered on Celite, rinsed with r\ > — r* £ 0 0 dichloromethane (50 cc) and concentrated under reduced pressure at a temperature in the vicinity of 50°C. Methyl 3-isocyanatophenylacetate (9.30 g) is thus obtained in the form of a yellow liquid stored under argon and used as it 5 is in subsequent syntheses.

Methyl 3-aminophenylacetate may be prepared in a fashion similar to that described in Example 10 §A, but starting from methyl 3-nitrophenylacetate (37.1 g) in solution in methanol (550 cc) and palladized charcoal 10 (2 g). Methyl 3-aminophenylacetate (28.2 g) is thus obtained in the form of a dark yellow liquid used as it is in subsequent syntheses.

Methyl 3-nitrophenylacetate may be prepared according to the method described by SEGERS and 15 A. BRUYLANTS, Bui. Soc. Chim. Belg., 64/ 87, (1955).

Example 22 By proceeding in a fashion similar to that described in Example 9, but starting from methyl (2RS,5SR)-3-{3-[2-(2-tert-butoxycarbony1-5-phenyl-l-pyrrolidinyl)-2-20 oxoethyl]ureido}phenylacetate (4.9 g) in solution in methanol (80 cc) and potassium hydroxide (0.56 g) dissolved in water (40 cc) and after treatment, (2RS,5SR)-3-{3-[2-(2-tert-butoxycarbony1-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}phenylacetic acid (1 g) is obtained [proton 25 NMR (200 MHz, DMSO D6, <5 in ppm) , 2 rotamers at room temperature, peak coalescence at 120°C: 1.5 (bs, 9H, (CHj)3); 3.5 (s, 2H, CH.CO) ; 6.8 to 7.7 (m, 9H, aromatic). Infrared spectrum (KBr), characteristic bands in cm"1: 3380, 3700 to 2250 with a maximum at 2625, 3155, 3110, 3090, 3060, 3030, 2975, 2930, 2880, 1735, 1635, 1610, 1595, 1560, 5 1495, 1450, 1395, 1365, 1310, 1225, 1155, 905, 890, 860, 840, 780, 760, 705].

Example 23 By proceeding in a fashion similar to that described in Example 1 but starting from ethyl (2RS,5SR)-5-10 phenylprolinate (2.2 g), 2-[3-(3-methyl- phenyl)ureido]acetic acid (2.1 g) in suspension in anhydrous 1,2-dichloroethane (50 cc) and sulphinyl chloride (0.72 cc), ethyl (2RS,5SR)-1-{2-[3-(3-methyl-phenyl)ureido]acetyl}-5-phenylprolinate (1.2 g), m.p. 15 115°C, is obtained after recrystallisation in acetonitrile. Ethyl (2RS,5SR)-5-phenylprolinate may be prepared according to the method described by F. LEONARD, GB Patent 997097, [C.A., 62P, 9109c (1965)].

Example 2 4 By proceeding in a fashion similar to that described in Example 3, but starting from N,N'-carbonyldiimidazole (4.1 g), ethyl (2RS,5SR)-1-(2-aminoacetyl)-5-phenylprolinate (7 g) in solution in anhydrous 1,2-dichloroethane (135 cc) and ethyl 62 3-aminobenzoate (4.1 g), ethyl (2RS,5SR)-l-{2-[3-(3-ethoxycarbonylphenyl)ureido]acetyl}-5-phenylprolinate (1.5 g), m.p. 136°C, is obtained.

Ethyl (2RS,5SR)-1-(2-aminoacetyl) -5-phenylprolinate may be prepared in a fashion similar to that described in Example 2 §A, but starting from ethyl (2RS,5SR)-1-(2-tert-butoxycarbonylaminoacetyl)-5-phenylprolinate (11.1 g) and iodotrimethylsilane (4.3 cc) in solution in anhydrous chloroform (150 cc). Ethyl (2RS,5SR)-1-(2-aminoacetyl)-5-phenylprolinate (7 g), used as it is in subsequent syntheses, is thus obtained.

Ethyl (2RS,5SR)-l-(2-tert-butoxv-carbonylaminoacetyl)-5-phenylprolinate may be prepared as described in Example 2 §B, but starting from a solution containing ethyl (2RS,5SR)-5-phenylprolinate (7 g), 2-tert-butoxycarbonylaminoacetic acid (5.6 g) and N,N'-dicyclohexylcarbodiimide (6.6 g) in anhydrous acetonitrile (65 cc). Ethyl (2RS,5SR)-l-(2-tert-butoxycarbonylaminoacetyl)-5-phenylprolinate (11.1 g) is thus obtained in the form of an orange oil, used as it is in subsequent syntheses.

Example 25 By proceeding in a fashion similar to that described in Example 1, but starting from cyclopropyl-methyl (2RS,5SR)-5-phenylprolinate (2 g), 2-[3-(3-methylphenyl)ureido]acetic acid (1.7 g) in suspension 2 4 3 5 63 in anhydrous 1,2-dichloroethane (50 cc) and sulphinyl chloride (0.6 cc), cyclopropylmethyl (2RS,5SR)-l-{2-[3-(3-methylphenyl)ureido}acetyl-5-phenylprolinate (1.1 g), m.p. 130°C, is obtained after recrystallisation in acetonitrile.

A - Cyclopropylmethyl (2RS,5SR)-5-phenylprolinate may be prepared as follows: iodotrimethylsilane (1.5 cc) is added dropwise to a solution of cyclopropylmethyl (2RS,5SR)-1-(tert-butoxycarbonyl)-5-phenylprolinate (3.5 g) in anhydrous chloroform (50 cc). The reaction mixture is stirred for 20 hours at a temperature in the vicinity of 25°C, then concentrated to dryness under reduced pressure at temperature of 45°C. The crude product obtained is purified by chromatography on silica [eluent: dichloromethane/methanol (97/3 by volume)]. The fractions containing the expected product are combined, then concentrated to dryness under reduced pressure. Cyclopropylmethyl (2RS,5SR)-5-phenylprolinate (2 g) is thus obtained in the form of an orange oil, used as it is in subsequent syntheses.

B - Cyclopropylmethyl (2RS,5SR)-l-(tert-butoxycarbonyl )-5-phenylprolinate may be prepared as follows: cyclopropylmethanol (1.8 g) is added dropwise while stirring at a temperature in the vicinity of 0°C to a solution of (2RS,5SR)-l-(tert-butoxycarbonyl)-5-phenylproline (7 g) and para-toluenesulphonyl chloride (4.6 g) in anhydrous pyridine (40 cc). After returning 64 to a temperature of 20°C, stirring is continued for 20 hours, the mixture is then poured into water (100 cc) and the product extracted with ethyl acetate (3 x 100 cc). The combined organic phases are washed with water (2 x 100 cc), with an N aqueous hydrochloric acid solution (2 x 100 cc), with an N aqueous sodium hydroxide solution (2 x 100 cc), then with water (3 x 100 cc), dried over magnesium sulphate and concentrated to dryness under reduced pressure at a temperature in the vicinity of 45°C. The crude product obtained is purified by chromatography on silica [eluent: dichloromethane/methanol (97/3 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at a temperature in the vicinity of 45°C. Cyclopropylmethyl (2RS,5SR)-1-(tert-butoxycarbonyl-5-phenylprolinate (3.6 g) is thus obtained in the form of an orange oil, used as it is in subsequent syntheses.

C - (2RS,5SR)-l-(tert-butoxycarbonyl)-5-phenylproline may be prepared as follows; di-tert-butyl dicarbonate (21.8 g) in solution in dioxane (120 cc) is added dropwise to a solution of (2RS,5SR)-5-phenyl-proline hydrochloride (22.8 g) and sodium carbonate (22 g) in water (160 cc) with stirring. The reaction mixture is stirred for 20 hours at a temperature in the vicinity of 20°C and then the precipitate formed is removed by filtration. The filtrate is washed with ethyl acetate (2 x 100 cc) and acidified to a pH of 1 65 by a 4N aqueous hydrochloric acid solution. The acid aqueous phase is extracted with dichloromethane (3 x 150 cc). The combined organic extracts are washed with water (2 x 50 cc), dried over magnesium sulphate 5 and concentrated to dryness under reduced pressure at a temperature in the vicinity of 40°C. After recrystallisation in aceto-nitrile, (2RS,5SR)-l-(tert-butoxycarbonyl)-5-phenyl-proline (24 g), m.p. 170°C, is obtained.

Example 26 By proceeeding in a fashion similar to that described in Example 1, but starting from isopropyl (2RS,5SR)-5-phenylprolinate (3 g), 2—[3—(3-methyl-phenyl)ureido]acetic acid (2.7 g) in a suspension in 15 anhydrous 1,2-dichloroethane (75 cc) and sulphinyl chloride (1 cc), isopropyl (2RS,5SR)-l-{2-[3-(3-methylphenyl)ureido]acetyl}-5-phenylprolinate (1.2 g) is obtained after purification [proton NMR (200 MHz, CDC13, s in ppm), 2 rotamers at room temperature, 20 preponderant rotamer description: 1.1 (d, 6H, (CH3)2); 1.7 to 2.5 (m, 4H, H in position 3 and 4 on pyrrolidine); 2.15 (s, 3H, CH3); 3 and 4.1 (2bd, 2H, CH2N); 4.4 (bt, 1H, H in position 2 on pyrrolidine); 4.9 (m, 2H, isopropyl CH and H in position 5 on 25 pyrrolidine); 6.6 to 7.5 (m, 9H, aromatic). Infrared spectrum (KBr), characteristic bands in cm"1: 3365, 3150, 3060, 3030, 2980, 2935, 2875, 1738, 1700, 1645, 24 3 5 1 4 66 1615, 1595, 1560, 1495, 1450, 1430, 1375, 1305, 1295, 1280, 1210, 1190, 1145, 1120, 915, 890, 860, 780, 755 705] .

Isopropyl (2RS,5SR)-5-phenylprolinate may be prepared in a fashion similar to that described in Example 25 §A, but starting from isopropyl (2RS,5SR)-1-(tert-butoxycarbonyl)-5-phenylprolinate (5 g) and iodotrimethylsilane (2.4 cc) in solution in anhydrous chloroform (50 cc). Isopropyl (2RS,5SR)-5-phenylprolinate (3 g) is thus obtained in the form of a yellow oil, used as it is in subsequent syntheses.

Isopropyl (2RS,5SR)-1-(tert-butoxycarbonyl)-5-phenylprolinate may be prepared as described in Example 25 §B, but starting from (2RS,5SR)-l-(tert-butoxycarbonyl )-5-phenylproline (5.85 g), para-toluene-sulphonyl chloride (3.85 g) and 2-propanol (1.6 g) in anhydrous pyridine (30 cc). After treatment, isopropyl (2RS,5SR)-1-(tert-butoxycarbonyl)-5-phenylprolinate (5 g) is obtained in the form of a yellow oil, used as it is in subsequent syntheses.

Example 27 The enantiomers of tert-butyl (2RS,5SR)-l-'(2-[3-(3-methylphenyl)ureido]-acetyl>-5-phenylprolinate were separated by PIRCKLE-type chiral phase high performance liquid chromatography, using (D)-N-3,5-dinitrobenzoylphenylglycine, grafted on aminopropyl silica as the stationary phase packed in a 200 mm long 67 24 3 5 K column of 80 mm diameter with, as the mobile phase, a hexane/2-propanol/methylene chloride mixture (85/7.5/7.5). The racemic mixture (1 g) yields: - tert-butyl (2S,5R)-l-{2-[3-(3-methylphenyl)ureido]-5 acetyl}-5-phenylprolinate (0.48 g), m.p. 79°C, [a)l° = +33.4° ±0.9° (c=l; methanol) [proton NMR (300 MHz, DMSO D6, S in ppm), 2 rotamers at room temperature, preponderant rotamer description: 1.5 (s, 9H, (CH3)3); 1.9 and 2.2 (2m, 4H, H in position 3 and 4 on 10 pyrrolidine); 2.2 (s, 3H, CH3); 3.2 and 3.9 (ABX, 2H, CH2N; 4.35 (dd, 1H, H in position 2 on pyrrolidine); 5.20 (dd, 1H, H in position 5 on pyrrolidine; 6.30 (dd, 1H, NH); 6.70 (bd, 1H, H in position 4 on urea phenyl); 7.1 to 7.7 (m, 8H, aromatic); 8.7 (s, 1H, NH)]. - tert-butyl (2R,5S)-l-{2-[3-(3-methylphenyl)ureido]-acetyl}-5-phenylprolinate (0.48 g), m.p. 79°C, [a]l° = -31.6" ±0.8" (c=l; methanol).

The support may be prepared as follows: Aminopropyl silica (100 A - 10 ^m - NH2; Macherey-Nagel) 20 (600 g) in dimethylformamide (2 1) is suspended in a six litre three-necked flask. N-ll-tert-Butoxycarbonyl-aminoundecanoic acid anhydride (95 g) is added and the reaction mixture is stirred for 18 hours at a temperature in the vicinity of 20°C. The silica is 25 separated by filtration and washed successively with dichloromethane (2 x 1500 cc), then with dimethylformamide (2 x 1500 cc). The silica washed in l. „ . 68 this fashion is resuspended in dimethyl-formamide (2 1) and N-ll-tert-butoxycarbonylamino-undecanoic acid anhydride (95 g) is added, and the reaction mixture is then stirred for 18 hours at a temperature in the 5 vicinity of 20°C. The silica is separated by filtration, washed successively with dichloromethane (2 x 600 cc), with tetrahydrofuran (2 x 600 cc), with methanol (2 x 600 cc) and with diethyl ether (2 x 600 cc) and then dried under reduced pressure at a temperature 10 in the vicinity of 20°C. A silica (610 g) referred to by the designation "BOC-Cn-C3-silica" is thus obtained in the form of a white powder, the structure of which is confirmed by the infrared spectrum and for which the elemental analysis (found) is: C % = 8.8; H % = 1.7; 15 N % = 1.2.

"BOC-C11-C3-silica" silica (607 g) is suspended in a six litre three-necked flask in dichloromethane (2 1) and pyridine (69 cc). Dimethyloctylchlorosilane (530 cc) is added dropwise 20 and the reaction mixture is stirred for 16 hours at a temperature in the vicinity of 20°C. The solid obtained is separated by filtration and washed successively with dichloromethane (2 x 1 1), with methanol (2 x 1 1), with tetrahydrofuran (2 x 1 1), with dichloromethane 25 (2x11) and with diethyl ether (2 x 1 1), then dried under reduced pressure at a temperature in the vicinity of 20cC. A silica referred to by the designation "BOC-Cu-C3-silica-0-Si(CH3)2(CH2)7CH3" (712 g) is thus 24 3 5 1 4 69 obtained in the form of a white powder, the structure of which is confirmed by the infrared spectrum and for which the elemental analysis (found) is: C % = 12.1; H % = 2.4; N % = 1.0.

"B0C-Cn-C3-silica-0-Si(CH3)2(CH2)7CH3" silica (711 g) is suspended in a six litre three-necked flask in a 6 % by volume solution (2200 cc) of trifluoroacetic acid in dichloromethane. The reaction mixture is stirred for 5 hours at a temperature in the 10 vicinity of 20°C. The silica is separated by filtration and washed successively with dichloromethane (2x11),. with a dichloromethane/diisopropylethylamine (70/30 by volume) mixture (2 x 1 1), with dichloromethane (1 1), with tetrahydrofuran (2 x 1 1), with methanol 15 (2x11) and with diethyl ether (2 x 1 1), then dried under reduced pressure at a temperature in the vicinity of 50 °C. The silica washed and dried in this fashion is resuspended in a 6 % by volume solution (2 1) of trifluoroacetic acid in dichloromethane. The reaction 20 mixture is stirred for 16 hours at a temperature in the vicinity of 20°C. The silica is separated by filtration and washed successively with dichloromethane (2 x 1.5 1), with a dichloromethane/diisopropylethylamine (70/30 by volume) mixture (2x11), with 25 dichloromethane (1.5 1), with tetrahydrofuran (2 x 2 1), with methanol (2 x 2 1) and with diethyl ether (2 x 2 1), then dried under reduced pressure at a temperature in the vicinity of 50#C. A silica referred 70 to by the designation "Cu-C3-silica-0-Si(CH3)2(CH2)7CH3:' (607 g) is thus obtained in the form of a white powder, the structure of which is confirmed by the infrared spectrum and for which the elemental analysis (found) 5 is: C % = 8.8; H % = 1.7; N % = 1.3.

"Cu-C3-silica-O-Si(CH3)2(CH2)7CH3" silica (400 g) is suspended in a four litre three-necked flask in dimethylformamide (1800 cc). 3,5-Dinitrobenzoyl-D-phenylglycine (42 g) and 2-ethoxy-l-ethoxycarbonyl-l,2-10 dihydroquinoline (30 g) are added and the reaction mixture is stirred for 16 hours at a temperature in the -vicinity of 20°C. The silica is separated by filtration and washed successively with dichloromethane (2 x 1 1), with tetrahydrofuran (2 x 1 1), with methanol (2 x 1 1) 15 and with diethyl ether (2 x 1 1). The silica washed in this way is resuspended in dimethylformamide (2 1) and 2-ethoxy-l-ethoxycarbonyl-l,2-di-hydroquinoline (30 g) and 3,5-dinitrobenzoyl-D-phenyl-glycine (42 g) are added, then the reaction mixture is stirred for 5 hours 20 at a temperature in the vicinity of 20°C. The silica is separated by filtration, washed successively with dimethylformamide (2 x 11)/ with dichloromethane (2 x 1 1), with tetrahydrofuran (2 x 1 1), with methanol (2 x 1 1) and with diethyl ether (2 x 1 1), 25 and then dried under reduced pressure at a temperature in the vicinity of 140°C. A silica referred to by the designation "DNB-D-Phg-Cu-C3-silica-OSi(CH3)2-(CH2)7CH3" (434 g) is thus obtained in the form of a white powder, the structure of which is confirmed by the infrared spectrum and for which the elemental analysis (found) is: C % = 12.3; H % = 1.8; N % = 2.1.

" DNB-D-Phg-Cn-C3-silica-OSi (CH3) 2( CH2) 7CH3" silica (434 g) is suspended in a four litre three-necked flask in dichloromethane (1.3 1) and dimethyloctylmethoxysilane (100 cc) is added, and then the reaction mixture is stirred for 54 hours at a temperature in the vicinity of 20°C. The silica is separated by filtration, washed successively with dichloromethane (2 x 1 1), with methanol (2 x 1 1), with tetrahydrofuran (2 x 1 1) and with dichloromethane (2 x 1 1), then dried under reduced pressure at a temperature in the vicinity of 140°C. A silica referred to by the designation "reoctylated DNB-D-Phg-Cu-C3-silica-OSi(CH3)2(CH2)7CH3" (425 g) is thus obtained in the form of a white powder, the structure of which is confirmed by the infrared spectrum and for which the elemental analysis (found) is: C % = 12.7; H % = 1.9; N % = 2.0.

"Reoctylated DNB-D-Phg-Cn-C3-silica-OSi(CH3)2-(CH2)7CH3" silica (425 g) is suspended in a four litre three-necked flask in dichloromethane (1.3 1). Trimethyl-silylimidazole (545 cc) is added dropwise and the reaction mixture is stirred for 15 hours at a temperature in the vicinity of 20°C. The solid obtained is separated by filtration and washed successively with tetrahydrofuran (2 x 1 1), with methanol (2 x 1 1), 24 3 5:4 72 with acetone (2x11) and with dichloromethane (2 x 1 1), then dried under reduced pressure at a temperature in the vicinity of 20°C. A silica referred to by the designation "DNB-D-Phg-Cn-C3-silica-5 [0Si(CH3)2(CH2)7CH3]-[0-Si(CH3)3]" (431 g) is thus obtained in the form of a white powder, the structure of which is confirmed by the infrared spectrum and for which the elemental analysis (found) is: C % = 13.7; H % = 2.2; N % = 2.0. 10 N-ll-tert-Butoxycarbonylaminoundecanoic acid anhydride may be prepared as follows: in the space of 10 minutes, a solution of N,N'-dicyclohexylcarbodiimide (10.63 g) in ethyl acetate (120 cc) is added to a solution of N-ll-tert-15 butoxycarbonylaminoundecanoic acid (30.1 g) in ethyl acetate (480 cc), kept at a temperature in the vicinity of 5°C. The reaction mixture is stirred for 1 hour at a temperature in the vicinity of 5°C, then for 16 hours at a temperature in the vicinity of 20°C. The 20 precipitate formed is separated by filtration and washed with ethyl acetate (30 cc). The filtrate is concentrated under reduced pressure at 30°C. The solid obtained is dried under vacuum at a temperature in the vicinity of 30°C. N-ll-tert-Butoxycarbonylamino-25 undecanoic acid anhydride (31 g), m.p. 58°C, is thus obtained.

N-ll-tert-Buxotycarbonylaminoundecanoic acid may be prepared according to the method described by 73 J.T. SPARROW, J. Org. Chem., 41, 1350 (1976).

Example 28 3-Methylphenyl isocyanate (0.05 cc) is added to a solution of tert-butyl (2S,5R)-l-(2-aminoacetyl)-5 5-phenylprolinate (0.08 g) in anhydrous tetrahydrofuran (10 cc). The reaction mixture is stirred for 3 hours at a temperature in the vicinity of 25°C, the solvent is then evaporated under reduced pressure at 45°C. The crude product obtained is purified by chromatography on 10 silica [eluent: dichloromethane/methanol (98/2 by volume)].The fractions containing the expected product are combined and concentrated to dryness under reduced pressure. tert-Butyl (2S,5R)-l-{2-[3-(3-methylphenyl)-ureido]acetyl}-5-phenylprolinate (0.04 g) is thus 15 obtained, the analytical data for which are in agreement with those for the dextrorotatory enantiomer prepared by chiral stationary phase chromatography of the racemic product, ([q]d° = +35.6° ±0.8° (C = 0.11 %; MeOH)). tert-Butyl (2S,5R)-1-(2-aminoacetyl)-5- phenylprolinate may be prepared as follows: concentrated sulphuric acid (0.1 cc) is added to a solution of (2S,5R)-l-(2-tert-butoxycarbonylamino-acetyl)-5-phenylpyrrolidine-2-carboxylic acid (0.08 g) 25 in chloroform (20 cc) cooled to 5°C. The reaction mixture is saturated with isobutene for 2 hours while stirring and maintaining the temperature at 5°C. After 74 returning to a temperature in the vicinity of 20#C, stirring is continued for 20 hours. The solution is brought to a pH of 8 by addition of a 10 % aqueous sodium bicarbonate solution and the aqueous phase is 5 separated, then extracted with chloroform (3 x 30 cc). The combined organic phases are washed with water (2 x 10 cc), dried over magnesium sulphate and concentrated to dryness under reduced pressure at 4 0°C. tert-Butyl (2S,5R)-1-(2-aminoacetyl)-5-phenylprolinate 10 (0.08 g) is thus obtained in the form of a yellow-orange oil, used as it is in subsequent syntheses. (2S,5R)-l-(2-tert-Butoxycarbonylaminoacetyl)-5-phenylpyrrolidine-2-carboxylic acid may be prepared as follows: a IN aqueous sodium hydroxide solution 15 0.5 cc is added to a solution of methyl (2S,5R)-1-(2-tert-butoxycarbonylaminoacetyl)-5-phenylprolinate (0.16 g) in a dioxane/water (70/30 by volume) mixture (15 cc) cooled to 5°C. After returning to a temperature in the vicinity of 20°C, stirring is continued for 12 20 hours, then a IN aqueous sodium hydroxide solution (0.5 cc) is added again. After stirring for 3 hours at a temperature in the vicinity of 20°C, the reaction mixture is washed with ether (2 x 10 cc), then brought to a pH in the vicinity of 2 by addition of a 0.1N 25 aqueous hydrochloric acid solution (20 cc). The reaction mixture is extracted with ethyl acetate (3 x 40 cc). The combined organic phases are dried over magnesium sulphate and concentrated to dryness under 2 4 ?> r 1 75 reduced pressure at 35°C. (2S,5R)-l-(2-tert-Butoxy-carbonylaminoacetyl) -5-phenylpyrrolidine-2-carboxylic acid (0.09 g) is thus obtained in the form of a colourless resin, used as it is in subsequent 5 syntheses.

Methyl (2S,5R)-1-(2-tert-butoxycarbonyl-aminoacetyl)-5-phenylprolinate may be prepared as follows: N,N'-dicyclohexylcarbodiimide (0.12 g) is added in one portion to a solution of methyl (2S,5R)-5-10 phenylprolinate (0.1 g) and 2-tert-butoxycarbonyl-aminoacetic acid (0.1 g) in anhydrous acetonitrile (10 cc) kept at a temperature in the vicinity of 0°C. The reaction mixture is stirred for 16 hours at a temperature in the vicinity of 25°C, then the insoluble 15 product is separated by filtration and washed with dichloromethane (3x5 cc). The filtrate is concentrated to dryness under reduced pressure at 40°C. The oily residue obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by 20 volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. Methyl (2S,5R)-l-(2-tert-butoxy-carbonylaminoacetyl)-5-phenylprolinate (0.16 g) is thus obtained in the form of a colourless oil, used as it is 25 in subsequent syntheses.

Methyl (2S,5R)-5-phenylprolinate may be prepared as follows: iodotrimethylsilane (0.45 cc) is added dropwise at a temperature in the vicinity of 25°C to a solution of methyl (2S,5RS)-l-methoxycarbonyl-5-phenylprolinate (0.6 g) in chloroform (15 cc). The mixture is heated under reflux for 18 hours. After cooling to a temperature in the vicinity of 25°C, water (20 cc) is added. The aqueous phase is separated, then extracted with chloroform (2 x 20 cc). The organic phases are combined, washed with water (2 x 10 cc), dried over magnesium sulphate and concentrated to dryness under reduced pressure at 40°C. The mixture of the two diastereoisomers obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclo-hexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. Methyl (2S,5R)-5-phenylprolinate (0.12 g) is thus obtained in the form of an oil used as it is in subsequent syntheses.

Methyl (2S,5RS)-1-methoxycarbonyl-5-phenylprolinate may be prepared as follows: aluminium trichloride (3.1 g) is added to a solution of methyl (2S,5RS)-5-methoxy-l-methoxycarbonylprolinate (5.1 g) in benzene (400 cc) cooled to a temperature in the vicinity of 5°C. The reaction mixture is kept at a temperature in the vicinity of 25°C for 12 hours while stirring, then saturated aqueous sodium bicarbonate solution (50 cc) is added. The aluminium hydroxides are separated by filtration and washed with methylene chloride (2 x 20 cc). The combined organic phases are washed with water (2 x 50 cc), dried over magnesium 77 sulphate and concentrated to dryness under reduced pressure at 40°C. The oily residue obtained is purified by chromatography on silica [eluent: ethyl acetate/ cyclohexane (20/80 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. Methyl (2S,5RS)-l-raethoxycarbonyl-5-phenylprolinate (0.6 g) is thus obtained in the form of a pale yellow oil, a (40/60 by weight) mixture of the (2S,5R) and (2S,5S) isomers used as it is in subsequent syntheses.

Methyl (2S;5RS)-5-methoxy-l-methoxycarbonyl-prolinate may be prepared according to the method described by T. SHONO et al., J. Am. Chem. Soc., 104, 6697 (1982).

Example 29 The enantiomers of (2RS,5SR)-3-{3-[2-(2-tert-butoxycarbony1-5-phenyl-1-pyrrolidinyl)-2-oxoethyl]-ureido}benzoic acid were separated by PIRCKLE-type chiral phase high performance liquid chromatography, using (D)-N-3,5-dinitrobenzoylphenyl-glycine (440 g), grafted on aminopropyl silica, as the stationary phase, packed in a 220 mm long column of 70 mm diameter with, as the mobile phase, a heptane/2- propanol/trifluoroacetic acid (80/20/0.05 by volume) mixture. The racemic mixture (3.5 g) yields: - (2S,5R)—3—<3—[2—(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido>benzoic acid (0.72 g), ' *T FT L*i o 5 78 m.p. 204°C, [a]g° = +32.3° ±0.7° (c = 1.08; methanol). - (2R,5S)-3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido>benzoic acid (0.54 g), m.p. 140°C, [a3|° = -33.1° ±0.8° (c = 1.03; methanol).

Example 30 By proceeding in a fashion similar to that described in Example 2, but starting from cis-l-(2-aminoacetyl)-2,5-diphenylpyrrolidine (2 g) and 3-methylphenyl isocyanate (0.9 cc) in solution in 10 anhydrous tetrahydrofuran (25 cc), (2RS,5SR)-l-[2-(2,5-diphenyl-l-pyrrolidinyl)-2-oxoethyl]-3-(3-methylphenyl) urea (1.4 g), m.p. 168°C, is obtained after recrystallisation in 2-propanol. cis-l-(2-Aminoacetyl)-2,5-diphenylpyrrolidine 15 may be prepared in a fashion similar to that described in Example 2 §A, but starting from cis-l-(2-tert-butoxycarbonylaminoacetyl)-2,5-diphenylpyrrolidine (6.6 g) and iodotrimethylsilane (2.5 cc) in solution in anhydrous chloroform (70 cc). cis-l-(2-Aminoacetyl)-20 2,5-diphenylpyrrolidine (4.8 g) is thus obtained in the form of an orange oil, used as it is in subsequent syntheses.

Proton NMR (300 MHz, DMSO D6, 6 in ppm), 2 rotamers at room temperature, 1.8 to 2.4 (bm, 4H, CH2-25 CH2); 2.7 and 3.3 (bd, 2H, AB, CH2C02); 5.0 (bm, 1H, CHN); 5.2 (bm, 1H, CHN); 7.2 to 7.5 (m, 10H, aromatic).

Mass (electron impact, 70 eV, m/z), 280 (M+) , 79 263 (M+-NH2), 222 (M*-COCH2NH2), 91 (C6H5CH2+) . cis-1-(2-tert-Butoxycarbonylaminoacetyl)-2,5-diphenylpyrrolidine may be prepared as described in Example 2 SB, but starting from a solution of 2,5-5 diphenylpyrrolidine (mixture of the cis/trans isomers) (6.6 g), 2-(tert-butoxycarbonylamino)acetic acid (5.2 g) and N,N'-dicyclohexylcarbodiimide (6.1 g) in anhydrous acetonitrile (50 cc). After separation by chromatography on silica [eluent: dichloromethane/ 10 methanol (9 8/2 by volume)], cis-1-(2-tert-butoxy- carbonylaminoacetyl)-2,5-diphenylpyrrolidine (3.6 g) is obtained in the form of an orange oil, used as it is in subsequent syntheses. 2,5-Diphenylpyrrolidine (mixture of the 15 cis/trans isomers) may be prepared according to the method described by C. G. OVERBERGER, M. VALENTINE and J-P. ANSELME, J. Amer. Chem. Soc., 91, 687-94 (1969).

Example 31 By proceeding in a fashion similar to that 20 described in Example 9, but starting from ethyl (cis)-3-{3-[2-(2,5-diphenyl-l-pyrrolidinyl)-2-oxoethyl]-ureido}benzoate (3 g) in solution in methanol (50 cc) and potassium hydroxide (0.7 g) dissolved in water (20 cc) and after treatment and recrystallisation in 25 ethanol, (cis)-3-{3-[2-(2,5-diphenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}benzoic acid (2 g), m.p. 255°C, is obtained. 80 Ethyl (cis)-3-{3-[2-(2,5-diphenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}benzoate may be prepared in a fashion similar to that described in Example 3, but starting from cis-1-(2-aminoacetyl)-2,5 diphenylpyrrolidine (3.4 g), N,N'-carbonyldiimidazole (2.2 g) in solution in anhydrous 1,2-dichoroethane (75 cc) and ethyl 3-aminobenzoate (2 g). After purification, ethyl (cis)-3-{3-[2-(2,5-diphenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}benzoate (3 g) is obtained in the form of a white meringue-like product, used as it is in subsequent syntheses.

Example 32 Proceeding in a fashion similar to that described in Example 2, but starting from tert-butyl (2RS,5SR)-l-(2-aminoacetyl)-6-phenyl-2-piperidinecarboxylate (1.8 g) in solution in anhydrous tetrahydrofuran (30 cc), 3-methylphenyl isocyanate (0.7 cc) is added. After recrystallisation in diisopropyl ether, tert-butyl (2RS,5SR)-l-{2-[3-(3-methylphenyl)ureido]acetyl)-6-phenyl-2-piperidinecarboxylate (0.7 g), m.p. 123°C, is obtained tert-Butyl (2RS,5SR)-1-(2-aminoacetyl)-6-phenyl-2-piperidinecarboxylate may be prepared in a fashion similar to that described in Example 2 SA, but starting from tert-butyl (2RS,5SR)-l-(2-tert~butoxy-carbonylaminoacetyl)-6-phenyl-2-piperidinecarboxylate (5.9 g) and iodotrimethylsilane (2 cc) in solution in 2 4 :•f 4 81 anhydrous chloroform (50 cc). tert-Butyl (2RS,5SR)-1-(2-aminoacetyl)-6-phenyl-2-piperidinecarboxylate (1.8 g) is obtained in the form of an orange oil, used as it is in subsequent syntheses.

Mass (electron impact, 70 eV, m/z), 318 (M+), 159 (M+-COCH2NH2 and -C02tBu) . tert-Butyl (2RS,5SR)-1-(2-tert-butoxy-carbonylaminoacetyl)-6-phenyl-2-piperidinecarboxylate may be prepared as described in Example 2 §B, but 10 starting from a solution of tert-butyl (2RS,5SR)-6-phenyl-2-piperidinecarboxylate (5.1 g), 2-(tert-butoxycarbonyl-amino)acetic acid (3.4 g) and N,N'-dicyclohexylcarbo-diimide (4 g) in solution in anhydrous acetonitrile (90 cc). tert-Butyl (2RS,5SR)-1-15 (2-tert-butoxycarbonyl-aminoacetyl)-6-phenyl-2- piperiainecarboxylate (5.9 g) is obtained in the form of an orange oil, used as it is in subsequent syntheses. tert-Butyl (2RS,5SR)-6-phenyl-2-piperidine-20 carboxylate may be prepared in a fashion similar to that described in Example 1 §B, but starting from (2RS,5SR)-6-phenyl-2-piperidinecarboxylic acid hydrochloride (14 g) in suspension in a mixture of concentrated sulphuric acid (5 cc) in anhydrous 25 chloroform (250 cc). The mixture is saturated with isobutene. After treatment, tert-butyl (2RS,5SR)-6-phenyl-2-piperidinecarboxylate (5.2 g), m.p. 68°C, is obtained. 82 (2RS,5SR)-6-phenyl-2-piperidinecarboxylic acid hydrochloride may be prepared as follows: 6-phenyl-2,3,4,5-tetrahydro-2-pyridinecarboxylic acid hydrochloride (14 g) and platinum oxide (0.7 g) in suspension in ethanol (200 cc) are stirred for 3 hours at a temperature in the vicinity of 20°C under a hydrogen atmosphere (130 kPa). The catalyst is removed by filtration and the filtrate is concentrated to dryness under reduced pressure at 45°C. After recrystallisation in acetonitrile, (2RS,5SR)-6-phenyl-2-piperidinecarboxylic acid hydrochloride (14 g), m.p. 184°C, is obtained. 6-Phenyl-2,3,4,5-tetrahydro-2-pyridine-carboxylic acid hydrochloride may be prepared as follows: ethyl acetamidomalonate (38.3 g) is added to a solution of sodium ethylate, prepared from sodium (4.1 g) in anhydrous ethanol (180 cc). After stirring for 1 hour at a temperature in the vicinity of 20°C, 2-(3-chloropropyl)-2-phenyl-l,3-dioxolane (40 g) and potassium iodide (2.1 g) are poured into the mixture. The reaction mixture is heated under reflux for 24 hours, then concentrated to dryness under reduced pressure at a temperature in the vicinity of 45°C. The pasty residue is taken up in dichloromethane (400 cc), washed with water (3 x 100 cc), dried over magnesium sulphate and concentrated to dryness under reduced pressure. The crude product is purified by chromatography on silica [eluent: dichloromethane]. The 83 fractions containing the expected product are combined and concentrated to dryness under reduced pressure. An orange oil (25 g) which is suspended in water (102 cc) and in 12N hydrochloric acid (102 cc) is thus obtained.

The reaction mixture is heated under reflux while stirring for 5 hours. After cooling, the acid solution is washed with diethyl ether (3 x 100 cc), then concentrated to dryness under reduced pressure at a temperature in the vicinity of 50°C. After 10 recrystallisation in acetonitrile, 6-phenyl-2,3,4,5-tetrahydro-2-pyridinecarboxylic acid hydrochloride (14 g), m.p. 146°C, is obtained. 2-(3-Chloropropyl)-2-phenyl-l,3-dioxolane may be prepared according to the method described by M. T. 15 WILLS, J. E. WILLS, L. Von DOLLEN, B.L. BUTLER and J. PORTER. J. Org. Chem., 45 (12), 2495 (1980).

Example 33 In the space of 10 minutes, a solution of N,N'-dicyclohexylcarbodiimide (0.48 g) in anhydrous 20 acetonitrile (10 cc) is added to a suspension of tert-butyl (2S,5R)-5-(2-furyl)prolinate (0.5 g) and 2—[3—(3-methylphenyl)ureido]acetic acid (0.48 g) in an anhydrous mixture (50 cc) of acetonitrile/1,2-dichloroethane (80/20 by volume) kept at a temperature 25 in the vicinity of 0°C. The reaction mixture is stirred for 16 hours at a temperature in the vicinity of 25°C, then the insoluble product is separated by filtration 84 and washed with dichloromethane (3 x 5 cc). The filtrate is concentrated to dryness under reduced pressure at 40 °C. The oily residue obtained is purified by chromatography on silica [eluent: ethyl 5 acetate/cyclohexane (40/60 by volume)]. The fractions containing the expected product are combined, then concentrated to dryness under reduced pressure at 40°C. After recrystallisation in an ethyl acetate/cyclohexane (50/50 by volume) mixture, tert-butyl (2S,5R)-5-(2-10 furyl)-l-{2-[3-(3-methylphenyl)ureido]acetyl}prolinate (0.15 g), m.p. 144°C, is obtained ([q]d° = +4.8° ±0.8° (C = 0.51%; MeOH)) [proton NMR (250 MHz, DMSO D6, S in ppm). 2 rotamers at room temperature, coalescence at 120°C, description at 120°C: 1.50 (bs, 9H, (CH3)3); 2.10 15 (bm, 2H, CH2); 2.30 (bm, 2H, CH2) ; 2.30 (s, 3H, CH3); 3.8 and 4.0 (ABX, 2H, CH2N); 4.45 (bt, 1H, NCHCOO); 5.20 (bdd, 1H, NCHC); 6.15 (bt, 1H, NH); 6.40 (bdd, 1H, C^H^O, in position 4); 6.50 (bd, 1H, C4H40 in position 3); 6.70 (bd, 1H, N-C6H4-C in position 4); 7.15 to 7.25 20 (m, 3H, aromatic); 7.50 (bs, 1H, C<,H<,0 in position 5); 8.40 (bs, 1H, NH). Infrared spectrum (KBr), characteristic bands in cm"1: 3365, 2975, 2930, 2850, 1735, 1640, 1615, 1595, 1560, 1490, 1390, 1365, 1150, 780, 745, 695. tert-Butyl (2S,5R)-5-(2-furyl)prolinate may be prepared as follows: iodotrimethylsilane (1.77 cc) is added dropwise at a temperature in the vicinity of 25°C to a solution of tert-butyl (2S,5RS)-l-tert-butoxycarbonyl-5-(2-furyl)prolinate (3.8 g) in chloroform (50 cc). Stirring is continued for 30 minutes, and then water (20 cc) is added. The aqueous phase is separated, then 5 extracted with chloroform (2 x 20 cc). The organic phases are combined, washed successively with a saturated aqueous sodium bicarbonate solution (30 cc) and with water (2 x 30 cc), then dried over magnesium sulphate and concentrated to dryness under reduced 10 pressure at 40°C. The mixture of the two diastereoisomers obtained is separated by chromatography on silica [eluent: ethyl acetate/cyclohexane (20/80 by volume)]. The fractions containing the expected product are combined and 15 concentrated to dryness under reduced pressure at 40°C. tert-Butyl (2S,5R)-5-(2-furyl)prolinate (0.50 g) is thus obtained in the form of a yellow-orange oil, used as it is in subsequent syntheses. tert-Butyl (2S,5RS)-l-tert-butoxycarbonyl-5-(2-20 furyl)prolinate may be prepared as follows: para- toluenesulphonic acid (0.42 g) is added to a solution of tert-butyl (2S,5RS)-l-tert-butoxycarbonyl-5-methoxyprolinate (9.6 g) in furan (100 cc). The reaction mixture is stirred for 24 hours at a 25 temperature in the vicinity of 25°C, with subsequent addition of sodium bicarbonate (1 g). The heterogeneous medium is concentrated to dryness under reduced 86 pressure at a temperature in the vicinity of 30°C. The residue obtained is taken up in ethyl acetate (250 cc) and washed with water (2 x 50 cc). The organic phase is dried over magnesium sulphate and concentrated to 5 dryness under reduced pressure at 30°C. The oily residue obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (5/95 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 35°C. tert-Butyl (2S,5RS)-l-tert- butoxycarbonyl-5-(2-furyl)prolinate (3.8 g), m.p. 70°C, is thus obtained as a (30/70 by weight) mixture of the (2S,5R) and (2S,5S) isomers, used as it is in subsequent syntheses. tert-Butyl (2S,5RS)-l-tert-butoxycarbonyl-5-methoxy prolinate may be prepared according to the method described by T. SHONO et al., J. Am. Chem. Soc., 104, 6697 (1982), but starting from tert-butyl (2S)-l-tert-butoxycarbonylprolinate. tert-Butyl (2S)-l-tert-butoxycarbonylprolinate may be prepared according to the method described by S. YOSHIFUJI et al., Chem. Pharm, Bull., 34, 3873 (1986).

Example 34 3-Methylphenyl isocyanate (0.8 cc) is added to a £ 4 3 5 87 solution of tert-butyl (2R,4R)-3-(2-aminoacetyl)-2-phenyl-4-thiazolidinecarboxylate (2.0 g) in anhydrous tetrahydrofuran (25 cc). The reaction mixture is stirred for 12 hours at a temperature in the vicinity 5 of 25°C, then diluted with ethyl acetate (100 cc). The organic phase is washed with water (2 x 40 cc), dried over magnesium sulphate and concentrated to dryness under reduced pressure at 40°C. The crude product obtained is purified by chromatography on silica 10 [eluent: methylene chloride/methanol (98/2 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. After vigorous stirring in heptane, tert-butyl (2R, 4R)-3-{2-[3-(3-15 methylphenyl)ureido]acetyl}-2-phenyl-4- thiazolidinecarboxylate (0.5 g) is thus obtained in the form of a white amorphous powder ([a]" = +70.0° ±1.3° (C = 1.02%; CHC13)) [proton NMR (200 MHz, CDC13, 5 in ppm), 2 rotamers at room temperature, description 20 for the preponderant rotamer at 25°C: 1.45 (bs, 9H, (CH3)3) ; 2.2 (s, 3H, CH3) ; 3.2 (A2X, 2H, CH2S) ; 3.2 and 4.3 (ABX, 2H, CH2N); 4.9 (t, 1H, CHN); 6.1 (bdd, 1H, NH); 6.2 (s, 1H, SCHN); 6.8 to 7,7 (m, 9H, aromatic). Infrared spectrum (KBr), characteristic bands in cm"1: 25 3375, 2975, 2930, 1735, 1650, 1610, 1595, 1560, 1490, 1455, 1370, 1150, 780, 730, 695].

A - tert-Butyl (2R,4R)-3-(2-aminoacetyl)-2-phenyl-4- 88 thiazolidinecarboxylate may be prepared as follows: iodotrimethylsilane (0.9 cc) is added dropwise at a temperature in the vicinity of 25°C to a solution of tert-butyl (2R,4R)-3-(2-tert-butoxycarbonylamino-5 acetyl)-2-phenyl-4-thiazolidinecarboxylate (2.5 g) in chloroform (15 cc). The reaction mixture is stirred for 1 hour at a temperature in the vicinity of 25°C with subsequent addition of water (15 cc). The aqueous phase is separated, then extracted with chloroform (2 x 10 cc). 10 The organic phases are combined, washed successively with water (20 cc), with a saturated aqueous sodium bicarbonate solution (20 cc) and with water (20 cc), then dried over magnesium sulphate and concentrated to dryness under reduced pressure at 40°C. tert-Butyl 15 (2R,4R)-3-(2-aminoacetyl)-2-phenyl-4- thiazolidinecarboxylate (2 g) is thus obtained in the form of a pale yellow oil, used as it is in subsequent syntheses.

Proton NMR (200 MHz, DMSO D6, 6 in ppm), 2 rotamers at 20 room temperature. 1.5 (s, 9H, C(CH3)3), 2.9 to 4.2 (vbm, 4H, 2 CH2); 4.8 and 5.4 (2m, 1H, NCHCO); 6.2 and 6.55 (2s, 1H, NCHS); 7.2 to 7.8 (m, 5H, aromatic); 8.3 (vbs, 1H, NH3+).

B - tert-Butyl (2R,4R)-3-(2-tert-25 butoxycarbonylaminoacetyl)-2-phenyl~4- thiazolidinecarboxylate may be prepared as follows: in 89 the space of 30 minutes, a solution of N,N'-dicyclohexylcarbodiimide (29.1 g) in anhydrous acetonitrile (80 cc) is added to a solution of tert-butyl (2RS,4R)-2-phenyl-4-thiazolidinecarboxylate 5 (37.4 g) and 2-tert-butoxycarbonylaminoacetic acid (24.7 g) in anhydrous acetonitrile (150 cc), kept at a temperature in the vicinity of 0°C. The reaction mixture is stirred for 16 hours at a temperature in the vicinity of 25°C, then the insoluble product is 10 separated by filtration and washed with acetonitrile (3 x 20 cc). The filtrate is concentrated to dryness under reduced pressure at 45°C. The crude product is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions 15 containing the expected product are combined and concentrated to dryness under reduced pressure. tert-Butyl (2R,4R)-3-(2-tert-butoxycarbonylamino-acetyl)-2-phenyl-4-thiazolidinecarboxylate (39.6 g) is thus obtained in the form of a thick yellow oil, used as it 20 is in subsequent syntheses, ([a]c° = +60.3° ±1.1° (C = 0.98%; CHC13)) .

C - tert-Butyl (2RS,4R)-2-phenyl-4-thiazolidinecarboxylate may be prepared as follows: concentrated sulphuric acid (15 cc) is added dropwise 25 to a suspension of (2RS,4R)-2-phenyl-4- thiazolidinecarboxylic acid (53.7 g) in chloroform (590 cc) cooled to a temperature in the vicinity of 5#C. The 24 3 5 1 4 90 reaction mixture is saturated with isobutene for 5 hours while stirring and while maintaining the temperature at 5°C. After returning to a temperature in the vicinity of 20°C, stirring is continued for 20 5 hours. The solution is brought to a pH of 8 by addition of a saturated aqueous sodium bicarbonate solution, then the aqueous phase is separated and extracted with chloroform (2 x 300 cc). The combined organic phases are washed with water (2 x 300 cc), dried over 10 magnesium sulphate and concentrated to dryness under reduced pressure at 40°C. The oily residue obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (20/80 by volume)]. The fractions containing the expected product are combined, then 15 concentrated to dryness under reduced pressure. tert-Butyl (2RS,4R)-2-phenyl-4-thiazolidinecarboxylate (42.8 g) is thus obtained in the form of a pale yellow oil, a (40/60 by weight) mixture of the (2R,4R) and (2S,4R) isomers, used as it is in subsequent syntheses.

D - (2RS,4R)-2-Phenyl-4-thiazolidinecarboxylic acid may be prepared as follows: at a temperature in the vicinity of 50°C, benzaldehyde (2.3 cc) is added dropwise to a suspension of L-cysteine (2.4 g) in ethanol (35 cc). The reaction mixture is heated under 25 reflux for 2 hours. After cooling to a temperature in the vicinity of 25°C, the insoluble product is separated by filtration and washed successively with 91 ethanol (20 cc) and with diethyl ether (20 cc). (2RS,4R)-2-phenyl-4-thiazolidinecarboxylic acid (3.7 g), m.p. 190°C, used as it is in subsequent syntheses, is thus obtained.

Example 35 The operation is carried out in a fashion similar to that described in Example 34, but starting from tert-butyl (2S,4S)-3-(2 aminoacetyl)-2-phenyl-4-thiazolidinecarboxylate (0.3 g) and 3-methylphenyl 10 isocyanate (0.12 cc). After vigorous stirring in cyclohexane, tert-butyl (2S,4S)-3-{2-[3-(3-methylphenyl)ureido]acetyl}-2-phenyl-4-thiazolidinecarboxylate (0.16 g) is thus obtained in the form of an amorphous pale yellow powder ([a]" = 15 -62.0° ±1.1° (C = 1.02%; CHC13)). [Proton NMR (250 MHz, DMSO D5, S in ppm), 2 rotamers at room temperature, peak coalescence at 120°C, general description valid for the other products of the thiazolidine family (at 120°C): 1.50 (bs, 9H, (CH3)3); 2.3 (s, 3H, CH3); 3.25 and 3.5 20 (ABX, 2H, CH2S); 3.7 and 4.05 (ABX, 2H, CH2N); 5.0 (bd, 1H, CHN); 6.2 (bds, 1H, NH); 6.4 (bs, 1H, SCHN); 6.7 (bd, 1H, N-CgH^-C in position 4 or 6); 7.05 to 7.2 (m, 3H, N-C6H4-C in position 2, 4 and 5); 7.35 (m, 3H, C6H5); (bd, 2H, C6H5); 8.35 (bs, 1H, NH). Infrared spectrum 25 (KBr), characteristic bands in cm"1: 3380, 2990, 2940, 2860, 1745, 1650, 1615, 1600, 1560, 1495, 1460, 1375, 92 1155, 785, 735, 700] . tert-Butyl (2S,4S)-3-(2-aminoacetyl)-2-phenyl-4-thiazolidinecarboxylate may be prepared as in example 34 §A, but starting from tert-butyl (2S,4S)-3-(2-tert-butoxycarbonylaminoacetyl)-2-phenyl-4-thiazolidinecarboxylate (0.53 g) in iodotrimethylsilane (0.18 cc). tert-Butyl (2S,4S)-3-(2-aminoacetyl)-2-phenyl-4-thiazolidinecarboxylate (0.31 g) is thus obtained in the form of a pale yellow oil, used as it is in subsequent syntheses. tert-Butyl (2S,4S)-3-(2-tert-butoxycarbonylaminoacetyl)-2-phenyl-4- thiazolidinecarboxylate may be prepared as described in Example 34 SB, but starting from tert-butyl (2RS,4S)-2-phenyl-4-thiazolidinecarboxylate (0.75 g), 2-tert-butoxycarbonylaminoacetic acid (0.53 g) and N,N'-dicyclohexylcarbodiimide (0.62 g). tert-Butyl (2S,4S)-3-(2-tert-butoxycarbonylaminoacetyl)-2-phenyl-4-thiazolidinecarboxylate (0.56 g) is thus obtained in the form of a beige amorphous powder, used as it is in subsequent syntheses ([a]" = -52.4° ±1.1° (C = 1.01%; CHC13)) . tert-Butyl (2RS,4S)-2-phenyl-4-thiazolidinecarboxylate may be prepared as in Example 34 SC, but starting from (2RS,4S)-2-phenyl-4-thiazolidinecarboxylic acid ! "7 ? c h j ^ 93 (4.5 g), concentrated sulphuric acid (1.3 cc) and an excess of isobutene. tert-Butyl (2RS,4S)-2-phenyl-4-thiazolidinecarboxylate (1.5 g) is thus obtained in the form of a pale yellow oil, a (50/50 by weight) mixture 5 of the (2R,4S) and (2S,4S) isomers, used as it is in subsequent syntheses. (2RS,4S)-2-phenyl-4-thiazolidinecarboxylic acid may be prepared as in example 34 §D, but starting from D~ cysteine (3.0 g) and benzaldehyde (2.85 cc). (2RS,4S)-10 2-Phenyl-4-thiazolidinecarboxylic acid (4.5 g), m.p. 190°C, used as it is in subsequent syntheses is thus obtained.

Example 36 A solution of ethyl 3-aminobenzoate (0.97 g) in 15 chloroform (10 cc) is added to a solution of N,N'- carbonyldiimidazole (1.1 g) in chloroform (30 cc). The reaction mixture is stirred for 6 hours at a temperature in the vicinity of 25°C, with the subsequent addition of tert-butyl (2R,4R)-3-(2-20 aminoacetyl)-2-phenyl-4-thiazolidinecarboxylate (1.3 g) in solution in chloroform (10 cc). The reaction mixture is stirred for 24 hours at a temperature in the vicinity of 25°C, then washed successively with water (50 cc), with a 0.5 N aqueous hydrochloric acid 25 solution (40 cc) and with water (50 cc). The organic 94 phase is separated, dried over magnesium sulphate and concentrated to dryness under reduced pressure at 40°C. The oily residue obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (35/65 by 5 volume)] and the fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. After vigorous stirring in heptane, tert-butyl (2R,4R)-3-{2-[3-(3-ethoxy-carbonylphenyl)ureido]acetyl}-2-phenyl-4-10 thiazolidinecarboxylate (1.0 g) is thus obtained in the form of an amorphous white powder, m.p. 85eC ([a]" = +61.5° ±1.2° (C = 0.97%; CHC13)) [proton NMR (200 MHz, DMSO D6, 6 in ppm), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 15 120°C: 1.3 (s, 3H, CH3) ; 4.3 (q, 2H, CH20); 7.3 to 7.7 (m, 8H, aromatic); 8.0 (bs, 1H, N-C6Ht-C in position 2). Infrared spectrum (KBr), characteristic bands in cm"1: 3375, 2980, 2930, 1720, 1655, 1610, 1600, 1560, 1490, 1370, 1240, 1155, 760, 735, 700, 690].

Example 37 A solution of tert-butyl (2R,4R)-3-(2-aminoacetyl)-2-phenyl-4-thiazolidinecarboxylate (1.0 g) in chloroform (10 cc) is added to a solution of N,N'-carbonyldiimidazole (0.6 g) in chloroform (15 cc). The 25 reaction mixture is stirred for 2 hours at a temperature in the vicinity of 25°C, followed by the 95 addition of 2-(3-aminophenyl)ethanol (0.44 g) in solution in chloroform (5 cc). The reaction mixture is stirred for 12 hours at a temperature in the vicinity of 25 °C, then concentrated to dryness under reduced 5 pressure at 40°C. The oily residue obtained is purified by chromatography on silica [eluent: ethyl acetate] and the fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. After recrystallisation in 10 acetonitrile, tert-butyl (2R,4R)-3-{2-[3-(3-(2-hydroxyethyl)phenyl)ureido]acetyl}-2-phenyl-4-thiazolidinecarboxylate (0.18 g) is thus obtained in the form of white crystals, m.p. 164°C ([q]d° = +59.6° ±1.8° (C = 0.50%; DMF) [proton NMR (300 MHz, DMSO D6, & 15 in ppm), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 120°C: 2.7 and 3.60 (2t, 4H, CH2CH20); 6.8 (bd, 1H, N-C6H4-C in position 4 or 6); 7.05 to 7.20 (m, 3H, N-CgH^-C in position 2, 5 and 6); 7.3 (m, 3H, C6H5); 7.6 20 (d, 2H, C6H5) . Infra-red spectrum (KBr), characteristic bands in cm"1): 3320, 2975, 2930, 2880, 2850, 1740, 1660, 1610, 1590, 1560, 1510, 1480, 1450, 1365, 1150, 1060, 790, 730, 695].

Example 38 In the space of 2 hours, a solution of tert-butyl (2R,4R)-3-(2-aminoacetyl)-2-phenyl-4- 4 'i -j 96 thiazolidinecarboxylate (2.6 g) in anhydrous tetrahydrofuran (15 cc) is added to a solution of N,N'-carbonyldiimidazole (1.3 g) in anhydrous tetrahydrofuran (15 cc). The reaction mixture is stirred at a temperature in the vicinity of 25°C for 12 hours, then concentrated to dryness under reduced pressure at 40°C. The oily residue obtained is purified by chromatography on silica [eluent: ethyl acetate]. A solution of tert-butyl (2R,4R)-3-[2-(1-imidazolylcarboxamido)acetyl]-2-phenyl-4-thiazolidinecarboxylate (2.8 g) thus obtained and of methyl 3-aminophenylacetate (2.7 g) in toluene (100 cc) is heated under reflux for 4 hours. After cooling to a temperature in the vicinity of 25°C, the reaction mixture is washed successively with water (50 cc), with a IN aqueous hydrochloric acid solution (50 cc) and with water (2 x 50 cc). The organic phase is separated, dried over magnesium sulphate and concentrated to dryness under reduced pressure at 40°C. The oily residue obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (50/50 by volume)]. The fractions containing the expected product are combined, then concentrated to dryness under reduced pressure at 30°C. After vigorous stirring in heptane, methyl (2R,4R)-3-{3-[2-(4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido}phenyl-acetate (1.9 g) is thus obtained in the form of a pale beige powder, m.p. 69°C ([a]" = +59.1° ±1.2° (C = 0.55%; 97 CHC13) ) [proton NMR ( 200 MHz, DMSO D6, & in ppm), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 120°C: 3.7 (2s, 5H, CH2C02CH3); 6.8 (d, 1H, N-CgH^-C in position 4 5 or 6); 7.1 to 7.7 (m, 8H, aromatic). Infrared spectrum (KBr), characteristics bands in cm"1: 3370, 2980, 2950, 2930, 1740, 1650, 1610, 1595, 1560, 1495, 1370, 1240, 1155, 780, 735, 700].

Example 39 At a temperature in the vicinity of 5°C, lithium hydroxide (0.1 g) is added to a solution of methyl (2R,4R)-3-{3-[2-(4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido}phenylacetate (1.2 g) in a water/tetrahydrofuran (30/70 by volume) mixture 15 (25 cc). The reaction mixture is stirred for 12 hours at a temperature in the vicinity of 25°C, then concentrated to 5 cc under reduced pressure at 40°C. The solution obtained is diluted with water (50 cc), washed with ethyl ether (2 x 30 cc), then acidified to 20 a pH of 2 with a IN aqueous hydrochloric acid solution (2.8 cc). The insoluble product is separated by filtration, washed with water (3 x 10 cc), then dried in air. (2R,4R)-3-{3-[2-(4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido}phenylacetic 25 acid (0.7 g) , m.p. 140°C, is thus obtained ([a]" = +62.6° ±1.6° (C = 0.64%; DMF)) [proton NMR (200 MHz, 98 DMSO D6, 6 in ppm), 2 rotamers at room temperature, peak coalescence at 120"C, characteristic chemical shifts at 120°C: 3.60 (bs, 2H, CH2C02H) ; 6.8 (bd, 1H, N-C5H«-C in position 6); 7.15 to 7.80 (m, 8H, aromatic). Infrared 5 spectrum (KBr), characteristics bands in cm"1: 3385, 2985, 2945, 2625, 1735, 1650, 1615, 1600, 1560, 1500, 1375, 1240, 1155, 785, 735, 705].

Example 40 The operation is carried out in a fashion similar to 10 that described in Example 33, but starting from tert-butyl- (2RS,4R)-2-(2-fluorophenyl)-4-thiazolidine-carboxylate (3.5 g), 2-[3-(3-methylphenyl)ureido] acetic acid (2.3 g) and N,N'-dicyclohexylcarbodiimide (2.3 g). After vigorous stirring in heptane, tert-butyl 15 (2R,4R)-3-{2-[3-(3-methylphenyl)ureido]acetyl}-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (1.05 g) is thus obtained in the form of a white solid, m.p. 107°C ([q]d° = +61.8° ±1.5° (C = 0.66%; DMF)) [proton NMR (200 MHz, DMSO D6, S in ppm), 2 rotamers at room temperature, 20 peak coalescence at 120°C, characteristic chemical shifts at 120°C: 2.2 (bs, 3H, CH3); 6.7 (bd, 1H, N-C6H<-C in position 4 or 6); 7.1 to 7.40 (m, 6H, aromatic); 7.9 (bm, 1H, C5H4F in position 3). Infrared spectrum (KBr), characteristics bands in cm"1: 3370, 2975, 2925, 25 1735, 1645, 1615, 1590, 1560, 1490, 1460, 1370, 1150, 775, 760, 690]. 99 tert-Butyl (2RS,4R)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate may be prepared as described in Example 34 §C, but starting from (2RS,4R)-2-(2-fluorophenyl)-4-thiazolidinecarboxylic acid (5.7 g) in solution in chloroform (60 cc), concentrated sulphuric acid (1.5 cc) and an excess of isobutene. tert-Butyl (2RS,4R)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (5.8 g) is thus obtained in the form of a yellow oil, a (50/50 by weight) mixture of the (2R,4R) and (2S,4R) isomers, used as it is in subsequent syntheses. (2RS,4R)-2-(2-fluorophenyl)-4-thiazolidinecarboxylic acid may be prepared as described in Example 34 §D, but starting from L-cysteine (21.2 g) and 2-fluorobenzaldehyde (19.2 cc). (2RS,4R)-2-(2-fluorophenyl)-4-thiazolidinecarboxylic acid (28.2 g), m.p. 147°C, used as it is in subsequent syntheses, is thus obtained.

Example 41 At a temperature in the vicinity of 25°C, a 1M solution (13.7 cc) of tetrabutylammonium fluoride in tetrahydrofuran is added to a solution of 2-trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(3-methoxyphenyl)-3-thiazolidinyl]-2- 100 oxoethyl}ureido}benzoate (4.2 g) in tetrahydrofuran (80 cc). The reaction mixture is stirred for 12 hours at a temperature in the vicinity of 25 °C, then acidified with a IN aqueous sulphuric acid solution (15 5 cc). After extraction with ethyl acetate (3 x 50 cc), the combined organic phases are washed with water (60 cc), then extracted with a IN aqueous sodium hydroxide solution (2 x 20 cc). The aqueous phases are separated, washed with ethyl ether (2 x 40 cc), 10 acidified to a pH of 4 with a 4N aqueous sulphuric acid solution and extracted with ethyl ether (3 x 50 cc). The organic phases are combined, dried over magnesium Qnl r\h J* +* o anH rnnronf rafoH +■ r\ Hnrnocc nnHor m £>? < • m m w w» t » m ww jt ikwwm a. wwtuvwv* pressure at 30°C. The solid obtained is dissolved in 15 0.5 N aqueous sodium hydroxide solution (10 cc). The solution obtained is filtered and acidified with a IN aqueous hydrochloric acid solution (5 cc). The insoluble product is separated by filtration, washed with water (2 x 5 cc) and dried in air. (2R,4R)-3-{3-20 {2-[4-tert-butoxycarbonyl-2-(3-methoxyphenyl)-3- thiazolidinyl]-2-oxoethyl}ureido}benzoic acid (1.48 g), m.p. 125°C, is thus obtained, ([o]p° = +74° ±2° (C = 0.32%; DMF)) [proton NMR (200 MHz, DMSO D6, 5 in ppm), 2 rotamers at room temperature, peak coalescence 25 at 120°C, characteristic chemical shifts at 1208C: 3.8 (s, 3H, 0CH3); 6.85 (bd, 1H, 0-C6HA-C in position 4); 7.2 to 7.6 (m, 6H, aromatic); 8.0 (bs, 1H, N-C6H4- in 101 position 2). Infrared spectrum (KBr), characteristic bands in cm"1: 3380, 2975, 2930, 2830, 2600, 1715, 1690, 1655, 1600, 1555, 1490, 1370, 1230, 1150, 1050, 755, 690, 680].

A - 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert- butoxycarbonyl-2-(3-methoxyphenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}benzoate may be prepared as follows: in the space of 10 minutes, a solution of N,N'-dicyclohexylcarbodiimide (2.45 g) in anhydrous 10 tetrahydrofuran (10 cc) is added to a solution of tert-butyl (2RS,4R)-2-(3-methoxyphenyl)-4-thiazolidinecarboxylate (3.5 g) and 2-{3-[3-(2-trimethylsilylethoxycarbonyl)phenyl]ureido}acetic acid (4.0 g) in anhydrous tetrahydrofuran (20 cc) cooled to 15 a temperature in the vicinity of 5°C. The reaction mixture is stirred for 16 hours at a temperature in the vicinity of 25°C. The insoluble product is separated by filtration and washed with tetrahydrofuran (2 x 10 cc). The filtrate is concentrated to dryness under reduced 20 pressure at 40°C. The oily residue obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. 25 2-trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert- butoxycarbonyl-2-(3-methoxyphenyl)-3-thiazolidinyl]-2- 24 3 5 1 4 102 oxoethyl}ureido}benzoate (4.85 g) is thus obtained in the form of an amorphous beige powder, used as it is in subsequent syntheses, ([q]d°= +67.2° ±1.3° (C = 0.52%; CHC13)).

B - tert-Butyl (2RS,4R)-2-(3-methoxyphenyl)-4- thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 34 §c, but starting from (2RS,4R)-2-(3-methoxyphenyl)-4-thiazolidinecarboxylic acid (14.0 g), concentrated 10 sulphuric acid (3.0 cc) and an excess of isobutene. The crude product obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced 15 pressure at 40°C. tert-Butyl (2RS,4R)-2-(3- methoxyphenyl)-4-thiazolidinecarboxylate (11.0 g) is thus obtained in the form of a yellow oil, a (40/60 by weight) mixture of the (2R,4R) and (2S,4R) isomers, used as it is in subsequent syntheses.

C - (2RS,4R)-2-(3-Methoxyphenyl)-4- thiazolidinecarboxylic acid may be prepared as described in Example 34 §D, but starting from L-cysteine (21.2 g) and 3-methoxybenzaldehyde (23 cc). (2RS,4R)-2-(3-methoxyphenyl)-4-thiazolidinecarboxylic 25 acid (38.0 g), m.p. 171°C, used as it is in subsequent V< 7 " 103 syntheses, is thus obtained.

D - 2-{3-[3-(2-Trimethylsilylethoxy-carbonyl)phenyl]ureido}acetic acid may be prepared as follows: a solution of potassium hydroxide (4.45 g) in 5 water (160 cc) is added to a solution of 2-trimethylsilylethyl 3-(3- ethoxycarbonylmethylureido)benzoate (24.7 g) in tetrahydrofuran (500 cc). The reaction mixture is stirred for 12 hours at a temperature in the vicinity 10 of 25°C, then concentrated to 150 cc under reduced pressure at 4 0°C. The solution obtained is diluted with water (200 cc), washed with ethyl acetate (2 x 50 cc), acidified with a IN aqueous hydrochloric acid solution (68 cc) and extracted with ethyl ether (3 x 100 cc). 15 The organic phases are combined, dried over magnesium sulphate and concentrated to dryness under reduced pressure. After recrystallisation in diisopropyl ether, 2-{3-[3-(2-trimethylsilylethoxycarbonyl)-phenyl]ureido}acetic acid (17.2 g), m.p. 173°C, is 20 obtained.

E - 2-Trimethylsilylethyl 3-(3- ethoxycarbonylmethylureido)benzoate may be prepared as follows: a solution of ethyl 2-(l-imidazolylcarboxamido)acetate (29.5 g) and 2-25 trimethylsilylethyl 3-aminobenzoate (36.2 g) in toluene (1000 cc) is stirred under reflux for 3 hours. After 104 cooling to a temperature in the vicinity of 25°C, the reaction mixture is washed with water (3 x 50 cc), dried over magnesium sulphate and concentrated to dryness under reduced pressure at 40°C. The oily 5 residue obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (40/60 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. 2-Trimethylsilylethyl 3-(3-10 ethoxycarbonylmethylureido)benzoate (24.7 g) is thus obtained in the form of a thick yellow oil, used as it -is in subsequent syntheses.

F - Ethyl 2-(1-imidazolylcarboxamido)acetate may be prepared as follows: in the space of 2 hours, ethyl 2-15 aminoacetate hydrochloride (42.3 g) is added to a solution of N,N'-carbonyldiimidazole (50.0 g) and triethylamine (43 cc) in anhydrous tetrahydrofuran (800 cc). The mixture is stirred for 24 hours at a temperature in the vicinity of 25°C, then the insoluble 20 product is separated by filtration and washed with tetrahydrofuran (2 x 50 cc). The filtrate is concentrated to dryness under reduced pressure at 40°C. The oily residue obtained is purified by chromatography on silica [eluent: ethyl acetate]. The fractions 25 containing the expected product are combined and concentrated to dryness under reduced pressure. Ethyl 2-(1-imidazolylcarboxamido)acetate (36.7 g) , 24 35 105 m.p. 103"C, is thus obtained.

G - 2-Trimethylsilylethyl 3-aminobenzoate may be prepared as follows: 5% palladium on charcoal (2.1 g) is added to a solution of 2-trimethylsilylethyl 3-5 nitrobenzoate (42.7 g) in ethanol (600 cc). The suspension is stirred for 2 hours at a temperature in the vicinity of 25°C under a hydrogen atmosphere (100 kPa). The catalyst is then separated by filtration and the filtrate is concentrated to dryness under reduced 10 pressure at 40°C. 2-Trimethylsilylethyl 3-aminobenzoate-(36.2 g) is thus obtained in the form of an oil used as it is in subsequent syntheses.

H - 2-Trimethylsilylethyl 3-nitrobenzoate may be prepared as follows: a solution of 2-15 trimethylsilylethanol (41.8 g) in 1,2-dichloroethane (200 cc) and triethylamine (51 cc) is added to a solution of 3-nitrobenzoyl chloride (66.0 g) in 1,2-dichloroethane (1000 cc) cooled to 5#C. The reaction mixture is stirred for 12 hours at a temperature in the 20 vicinity of 25 °C, then the insoluble product is separated by filtration and washed with 1,2-dichloroethane (2 x 50 cc). The filtrate is concentrated to dryness under reduced pressure at 40#C. The oily residue obtained is purified by chromatography 25 on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product \ 106 are combined and concentrated to dryness under reduced pressure at 40°C. 2-Trimethylsilylethyl 3-nitrobenzoate (76.9 g) is thus obtained in the form of an oil used as it is in subsequent syntheses.

Example 42 The operation is carried out in a fashion similar to that described in Example 41, but starting from 2-trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-10 oxoethyl>ureido}benzoate (2.3 g) and 1M tetrabutylammonium fluoride solution (7.6 cc). The crude product is purified by chromatography on silica [eluent: ethyl acetate/methanol (90/10 by volume)]. The fractions containing the expected product are combined 15 and concentrated to dryness under reduced pressure at 40°C. After vigorous stirring in diisopropyl ether, (2R, 4R)-3-{2-{2-[4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-1- oxoethyl}ureido>benzoic acid (0.4 g) is thus obtained 20 in the form of an amorphous solid ([a]" = +68.3° ±1.8" (C = 0.57%; CHC13)) [proton NMR (200 MHz, DMSO D6/ 5 in ppm), 2 rotamers at room temperature, peak coalescence at 120*0, characteristic chemical shifts at 120°C: 7.2 to 7.6 (m, 6H, aromatic); 7.9 (bt, 1H, F-C6H4 in 25 position 3, ^=9 Hz); 8.0 (bs, 1H, N-C6H4- in position 107 2). Infrared spectrum (KBr), characteristic bands in cm"1: 3380, 2980, 2930, 2600, 1735, 1690, 1655, 1610, 1590, 1555, 1490, 1455, 1370, 1230, 1150, 760, 680]. 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl ]-2-(2-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}benzoate may be prepared in a fashion similar to that described in Example 41 §A, but starting from tert-butyl (2RS,4R)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (3.35 g), 2-{3-[3-(2-trimethylsilylethoxycarbonyl)phenyl]ureido>acetic acid (4.0 g) and N,N'-dicyclohexylcarbodiimide (2.45 g). The crude product is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}benzoate (2.4 g) is thus obtained in the form of an amorphous beige solid, used as it is in subsequent syntheses ([a]" = +50.2° i 1.6° (C = 0.38%; CHC13)).

Example 43 The operation is carried out in a fashion similar to that described in Example 41, but starting from 24 3 5 1 108 2-trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(3-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}benzoate (1.6 g) in 1M tetrabutyl-aramonium fluoride solution (5.3 cc). The crude product 5 is purified by chromatography on silica [eluent; ethyl acetate/methanol (90/10 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. After vigorous stirring in diisopropyl ether, (2R,4R)-10 3-{3-{2-[4-tert-butoxycarbonyl-2-(3-fluorophenyl)-3- thiazolidinyl]-2-oxoethyl}ureido}benzoic acid (0.22 g) is thus obtained in the form of an amorphous solid ([«]d° = +79.0° +2.0° (C = 0.43%; CHC13)) [proton NMR (250 MHz, DMSO De, S in ppm), 2 rotamers at room 15 temperature, characteristic chemical shifts at 25°C; 1.5 (bs, 9H, (CH3) 3); 7.1 to 7.6 (m, 7H, aromatic); 8.0 (bs, 1H, N-C6Hi,- in position 2). Infrared spectrum (KBr), characteristic bands in cm"1: 3380, 2975, 2930, 2600, 1715, 1695, 1650, 1610, 1590, 1560, 1490, 1450, 20 1370, 1240, 1150, 780, 755, 685]. 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(3-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}benzoate may be prepared in a fashion similar to that described in Example 41 §A, but 25 starting from tert-butyl (2RS,4R)-2-(3-fluorophenyl)-4-thiazolidinecarboxylate (1.68 g), 2-{3-[3-(2- 109 trimethylsilylethoxycarbonyl)phenyl]ureido}acetic acid (2.0 g) and N,N'-dicyclohexylcarbodiimide (1.23 g). The crude product is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(3-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}benzoate (1.6 g) is thus obtained in the form of an amorphous beige solid, used as it is in subsequent syntheses ([a ]q°=+45 .7 ° ±1.5° (C = 0.53%; CHC13) ). tert-Butyl (2RS,4R)-2-(3-fluorophenyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 34 §C, but starting from (2RS,4R)-2-(3-fluorophenyl)-4-thiazolidinecarboxylic acid (11.4 g) in solution in chloroform (200 cc), concentrated sulphuric acid (3.0 cc) and an excess of isobutane. The crude product obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40#C. tert-Butyl (2RS,4R)-2-(3-fluorophenyl)-4-thiazolidinecarboxylate (10.3 g) is thus obtained in the form of a yellow oil, a (30/70 by 110 weight) mixture of the (2R,4R) and (2S,4R) isomers, used as it is in subsequent syntheses. (2RS,4R)-2-(3-fluorophenyl)-4-thiazolidinecarboxylic acid may be prepared as described in Example 34 §D, but starting from L-cysteine (21.2 g) and 3-fluorobenzaldehyde (20 cc). (2RS,4R)-2-(3-Fluorophenyl)-4-thiazolidinecarboxylic acid (30.2 g), m.p. 178°C, used as it is in subsequent syntheses, is thus obtained.

Example 44 The operation is carried out in a fashion similar to that described in Example 41, but starting from 2-trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(4-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}benzoate (2.0 g) and 1M tetrabutylammonium fluoride solution (6.6 cc). The crude product is purified by chromatography on silica [eluent: ethyl acetate]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. After vigorous stirring in diisopropyl ether, (2R,4R)-3-{2-{2-[4-tert-butoxycarbonyl-2-(4-fluorophenyl)-3-thiazolidinyl]-1-oxoethyl>ureido}benzoic acid (0.74 g), m.p. 154#C, is thus obtained ([a]" = +49.7° ±1.3° (C = 0.46%; DMF)) - {. 7 f« 1 £ f I.y -j I t 111 [proton NMR (250 MHz, DMSO D6, S in ppm), 2 rotamers at room temperature, characteristic chemical shifts at 25°C: 1.5 (bs, 9H, (CH3)3); 7.1 to 7.8 (m, 7H, aromatic); 8.0 (bs, 1H, N-C6H<,- in position 2). Infrared 5 spectrum (KBr), characteristic bands in cm"1: 3380, 2985, 2945, 2625, 1695, 1650, 1610, 1560, 1510, 1490, 1375, 1235, 1155, 800, 760, 685]. 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(4-fluorophenyl)-3-thiazolidinyl]-2-10 oxoethyl}ureido}benzoate may be prepared in a fashion similar to that described in Example 41 §A, but starting from: tert-butyl (2RS,4R)-2-(4-fluorophenyl)-4-thiazolidinecarboxylate (1.68 g), 2-{3-[3-(2-trimethylsilylethoxycarbonyl)phenyl]ureido}acetic acid 15 (2.0 g) and N,N'-dicyclohexylcarbodiimide (1.23 g). The crude product is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced 20 pressure at 40°C. 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(4-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}benzoate (2.0 g) is thus obtained in the form of an amorphous beige solid, used as it is in subsequent syntheses ([a]" = +46.6° 25 +1° (C = 0.50%; CHC13)) . 112 tert-Butyl (2RS,4R)-2-(4-fluorophenyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 34 §C, but starting from (2RS,4R)-2-(4-fluorophenyl)-4-5 thiazolidinecarboxylic acid (11.4 g), concentrated sulphuric acid (3.0 cc) and an excess of isobutene. The crude product obtained is purified by chromatography on silica gel [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product 10 are combined and concentrated to dryness under reduced pressure at 40°C. tert-Butyl (2RS,4R)-2-(4-fluorophenyl)-4-thiazolidinecarboxylate (10.0 g) is thus obtained in the form of a yellow oil, a (40/60 by weight) mixture of the (2R,4R) and (2S,4R) isomers, 15 used as it is in subsequent syntheses. (2RS,4R)-2-(4-Fluorophenyl)-4-thiazolidinecarboxylic acid may be prepared as described in Example 34 §D, but starting from L-cysteine (21.2 g) and 4-fluorobenzaldehyde (20 cc). (2RS,4R)-2-(4-20 Fluorophenyl)-4-thiazolidinecarboxylic acid (34.3g), m.p. 186°C, used as it is in subsequent syntheses, is thus obtained.

Example 45 The operation is carried out in a fashion similar to 25 that described in Example 41, but starting from 2- 113 trimethylsilylethyl (2R,4R)-3-{3-{2-^-tert-butoxycarbonyl^ - ( 2-chlorophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}benzoate (2.0 g) and 1M tetrabutylammonium fluoride solution (6.5 cc). The 5 crude product is purified by chromatography on silica [eluent: ethyl acetate/methanol (90/10 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. After vigorous stirring in diisopropyl ether, 10 (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(2- chlorophenyl)-3-thiazolidinyl]-2-oxoethyl}ureido>-benzoic acid (0.65 g) is thus obtained in the form of an amorphous solid ([q]q° = +88° ±2° (C = 0.39%; CHC13)) [proton NMR (200 MHz, DMSO D6/ S in ppm), 2 rotamers at 15 room temperature, peak coalescence at 120°C, characteristic chemical shifts at 120°C: 7.3 to 7.6 (m, 7H, aromatic); 7.95 (bs, 1H, N-C6H<- in position 2). Infrared spectrum (KBr), characteristic bands in cm"1: 3390, 2985, 2940, 2600, 1735, 1660, 1610, 1560, 1375, 20 1240, 1155, 755, 685]. 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(2-chlorophenyl)-3-thiazolidinyl]-2-oxoethyi)ureido}benzoate may be prepared in a fashion similar to that described in Example 41 §A, but 25 starting from tert-butyl (2RS,4R)-2-(2-chlorophenyl)-4-thiazolidinecarboxylate (1.6 g), 2-{3-[3-(2- 4 3 114 trimethylsilylethoxycarbonyl)phenyl]ureido}acetic acid (2.0 g) and N,N'-dicyclohexylcarbodiimide (1.23 g) . The crude product is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(2-chlorophenyl) -3-thiazolidinyl]-2-oxoethyl}ureido}benzoate (2.0 g) is thus obtained in the form of an amorphous beige solid, used as it is in subsequent syntheses, ([a]jj;0 = +87.0° ±2.0° (C = 0.46%; CHC13)) . tert-Butyl (2RS,4R)-2-(2-chlorophenyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 34 §C, but starting from (2RS,4R)-2-(2-chlorophenyl)-4-thiazolidinecarboxylic acid (12.2 g), concentrated sulphuric acid (3.0 cc) and an excess of isobutene. The crude product obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. tert-Butyl (2RS,4R)-2-(2-chlorophenyl)-4-thiazolidinecarboxylate (11.0 g) is thus obtained in the form of a yellow oil, a (40/60 by weight) mixture of the (2R,4R) and (2S,4R) isomers, 115 used as it is in subsequent syntheses. (2RS,4R)-2-(2-Chlorophenyl)-4-thiazolidinecarboxylic acid may be prepared as in Example 34 §D, but starting from L-cysteine (21.2 g) and 2-chlorobenzaldehyde 5 (25.8 g). (2RS,4R)-2-(2-chlorophenyl)-4- thiazolidinecarboxylic acid (21.9 g), m.p. 144°C, used as it is in subsequent syntheses is obtained.

Example 46 The operation is carried out in a fashion similar to 10 that described in Example 41, but starting from 2-trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(3-hydroxyphenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}benzoate (4.0 g) and 1M tetrabutylammonium fluoride solution (11.8 cc). The 15 crude product is purified by chromatography on silica [eluent: ethyl acetate]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. The solid residue is dissolved in a 0.5 N aqueous sodium 20 hydroxide solution (8.0 cc). The solution is filtered and acidified with a IN aqueous hydrochloric acid solution (4.1 cc). The insoluble product is separated by filtration, washed with water (2 x 5 cc) and dried in air. (2R,4R)-3-{3-(2-[4-tert-butoxycarbonyl-2-(3- 116 hydroxyphenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}-benzoic acid (0.65 g), m.p. 150 cc, is thus obtained. ([q]d° = +62° ±2° (C = 0.28%; DMF)) [proton NMR (200 MHz, DMSO D6, 6 in ppm), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 120°C: 6.8 (bd, 1H, 0-C6H4-C in position 4; 7.0 to 7.6 (m, 6H, aromatic); 8.0 (bs, 1H, N-C6H4- in position 2). Infrared spectrum (KBr), characteristic bands in cm"1: 3380, 2975, 2930, 2625, 1700, 1650, 1590, 1560, 1490, 1370, 1235, 1150, 785, 760, 690, 680]. 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl -2- ( 3-hydroxyphenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}benzoate may be prepared in a fashion similar to that described in Example 41 §A, but starting from tert-butyl (2RS,4R)-2-(3-hydroxyphenyl)-4-thiazolidinecarboxylate (1.66 g), 2-{3-[3-(2-trimethylsilylethoxycarbonyl)phenyl]ureido}acetic acid (2.0 g) and N,N'-dicyclohexylcarbodiimide (1.33 g). 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(3-hydroxyphenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}benzoate (4.0 g) is thus obtained in the form of an amorphous yellow powder used as it is in subsequent syntheses. tert-Butyl (2RS,4R)-2-(3-hydroxyphenyl)-4-thiazolidinecarboxylate may be prepared in a fashion 117 similar to that described in Example 34 §C, but starting from (2RS,4R)-2-(3-hydroxyphenyl)-4-thiazolidinecarboxylic acid (11.3 g) in solution in chloroform (200 cc), concentrated sulphuric acid 5 (3.0 cc) and an excess of isobutene. The crude product obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced 10 pressure at 40°C. tert-Butyl (2RS,4R)-2-(3- hydroxyphenyl)-4-thiazolidinecarboxylate (4.5 g) is thus obtained in the form of a yellow oil, a (50/50 by weight) mixture of the (2R,4R) and (2S,4R) isomers, used as it is in subsequent syntheses. (2RS, 4R) -2- (3-hydroxyphenyl) -4-thiazolidinecarboxylic acid may be prepared as in Example 34 §D, but starting from L-cysteine (21.2 g) and from 3-hydroxybenzaldehyde (22.8 g). (2RS,4R)-2-(3-Hydroxyphenyl)-4-thiazolidinecarboxylic acid (37.5 g), m.p. 207°C, used 20 as it is in subsequent syntheses, is thus obtained.

Example 47 The operation is carried out in a fashion similar to that described in Example 41, but starting from 2-trimethylsilylethyl (2R,4R)-3-{3-[2-(4-tert-25 butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2- 118 oxoethyl]ureido}benzoate (1.3 g) and a molar tetrabutylammonium fluoride solution (4.5 cc). The crude product is purified by chromatography on silica [eluent:ethyl acetate/methanol (95/5 by volume)]. The 5 fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. The solid residue is dissolved in 0.5 N aqueous sodium hydroxide solution (4.0 cc). The solution is filtered, and acidified with a IN aqueous hydrochloric 10 acid solution (2.1 cc). The insoluble product is separated by filtration, washed with water (2 x 5 cc) and dried in air. (2R,4R)-3-(3-[2-(4-tert-Butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido}benzoic acid (0.33 g), m.p. 134°C, is 15 thus obtained. ([a]J0 = +85° ±3° (C = 0.40%; CHC13)) [proton NMR (250 MHz, DMSO D6, 5 in ppm), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 120°C: 7.3 to 7.7 (m, 8H, aromatic); 8.0 (bs, 1H, N-C6H4-C in position 2). 20 Infrared spectrum (KBr), characteristic bands in cm"1: 3380, 2980, 2930, 2600, 1690, 1650, 1610, 1590, 1555, 1490, 1370, 1235, 1150, 760, 730, 700, 680]. 2-Trimethylsilylethyl (2R, 4R) -3-{3-[2-( 4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl) -2-25 oxoethyl]ureido}benzoate may be prepared in a fashion similar to that described in Example 38, but starting from tert-butyl (2R,4R)-3-[2-(l- 119 imidazolylcarboxamido) acetyl ]-2-phenyl-4-thiazolidinecarboxylate (1.7 g) and 2-trimethyl-silylethyl 3-aminobenzoate (1.2 g). The crude product is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40*C. 2-Trimethylsilylethyl (2R,4R)-3-{3-[2-(4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido>benzoate (1.3 g) is thus obtained in the form of an orange oil, used as such in subsequent syntheses.

Example 48 The operation is carried out in a fashion similar to that described in Example 41, but starting from 2-trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(4-dimethylaminophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}benzoate (4.0 g) and 1M tetrabutylammonium fluoride solution (4.2 cc). The crude product is purified by chromatography on silica [eluent: ethyl acetate/methanol (90/10 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. After vigorous stirring in diisopropyl ether, (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(4- ' '< £ 1 ' I "... -j I 120 dimethylaminophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}benzoic acid (0.35 g) is thus obtained in the form of an amorphous solid, ([a]" = +138" ±3° (C = 0.37%; CHC13) ) [proton NMR (200 MHz, DMSO D6, 6 in 5 ppm), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 120°C: 6.7 (bd, 2H, (Me)2N-C6HA in position 3 and 5); 7.3 and 7.6 (m, 5H, aromatic); 8.0 (bs, 1H, N-C6H,,- in position 2). Infrared spectrum (KBr), characteristic bands in cm"1: 10 3380, 2975, 2930, 2805, 2600, 1715, 1690, 1650, 1610, 1555, 1520, 1485, 1365, 1230, 1150, 815, 760, 685].

A - 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(4-dimethylaminophenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}benzoate may be 15 prepared in a fashion similar to that described in Example 41 §A, but starting from tert-butyl (2RS,4R)-2-(4-dimethylaminophenyl)-4-thiazolidinecarboxylate (1.66 g), 2-{3-[3-(2- trimethylsilylethoxycarbonyl)phenyl]ureido}acetic acid 20 (2.0 g) and N,N'-dicyclohexylcarbodiimide (1.23 g). The crude product is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced 25 pressure at 40°C. 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(4-dimethylaminophenyl)-3- 121 thiazolidinyl]-2-oxoethyl}ureido}benzoate (1.3 g) is thus obtained in the form of an amorphous beige solid, used as it is in subsequent syntheses, ([q]d°= +93° ±2° (C = 0.49%; CHC13) ).

B - tert-Butyl (2RS,4R)-2-(4-dimethylaminophenyl)-4-thiazolidinecarboxylate may be prepared as follows; iodotrimethylsilane (2.95 cc) is introduced dropwise at a temperature in the vicinity of 25°C to a solution of tert-butyl (2RS,4R)-3-tert-butoxycarbonyl-2-(4-10 dimethylaminophenyl)-4-thiazolidinecarboxylate (8.1 g) in chloroform (100 cc). The reaction mixture is stirred for 18 hours at this temperature,, followed by the addition of water (50 cc). The organic phase is separated, washed with a saturated aqueous sodium 15 bicarbonate solution (2 x 30 cc) and with water (2 x 30 cc), then extracted with a IN aqueous hydrochloric acid solution (3 x 30 cc). The aqueous phases are combined, washed with dichloromethane (2 x 20 cc), brought to a pH of 7 with a 4N aqueous 20 sodium hydroxide solution and extracted with dichloromethane (3 x 30 cc). The combined organic phases are dried over magnesium sulphate and concentrated to dryness under reduced pressure at 40°C. The oily residue obtained is purified by chromatography 25 on silica [eluent: diisopropyl ether]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure, tert- 122 Butyl (2RS,4R)-2-(4-dimethylaminophenyl)-4-thiazolidinecarboxylate (2.3 g), m.p. 142°C, a (50/50 by weight) mixture of the (2R,4R) and (2S,4R) isomers, used as it is in subsequent syntheses, is thus 5 obtained.

C - tert-Butyl (2RS,4R)-3-tert-butoxycarbonyl-2-(4-dimethylaminophenyl)-4-thiazolidinecarboxylate may be prepared as follows: tert-butanol (3.1 g) is added to a solution of 3-tert-butoxycarbonyl-2-(4-10 dimethylaminophenyl)-4-thiazolidinecarboxylic acid (14.8 g) and of para-toluenesulphonyl chloride (16.0 g) in anhydrous pyridine (70 cc), cooled to a temperature in the vicinity of 0°C. After returning to a temperature of 20°C, stirring is continued for 20 15 hours, then the mixture is poured into water (200 cc) and extracted with ethyl acetate (3 x 100 cc). The combined organic phases are washed successively with water (2 x 100 cc), with IN aqueous sodium hydroxide solution (2 x 100 cc) and with water (2 x 100 cc), then 20 dried over magnesium sulphate and concentrated to dryness under reduced pressure at 40°C. The crude product obtained is purified by chromatography on silica [eluent: diisopropyl ether]. The fractions containing the expected product are combined and 25 concentrated to dryness under reduced pressure at a temperature in the vicinity of 45°C. tert-Butyl (2RS,4R)-3-tert-Butoxycarbonyl-2-(4- 123 dimethylaminophenyl-4-thiazolidinecarboxylate (8.1 g) is thus obtained in the form of an orange oil, used as it is in subsequent syntheses.

D - (2RS,4R)-3-tert-Butoxycarbonyl-2-(4-5 dimethylaminophenyl)-4-thiazolidinecarboxylic acid may be prepared as follows: di-tert-butyl dicarbonate (10.9 g) in solution in dioxane (50 cc) is added dropwise while stirring to a solution of (2RS,4R)-2-(4-dimethylaminophenyl)-4-thiazolidinecarboxylic acid 10 (12.6 g) and sodium carbonate (5.25 g) in water (100 cc). The reaction mixture is stirred for 20 hours at a temperature in the vicinity of 20 °C, then the precipitate formed is separated by filtration. The filtrate is washed with ethyl acetate (2 x 100 cc), 15 acidified to a pH of 4 with a 4N aqueous hydrochloric acid solution, then extracted with ethyl acetate (3 x 100 cc). The combined organic phases are washed with water (2 x 50 cc), dried over magnesium sulphate and concentrated to dryness under reduced pressure at 20 40°C. After recrystallisation in diisopropyl ether, (2RS,4R)-3-tert-butoxycarbonyl-2-(4-dimethylaminophenyl)-4-thiazolidinecarboxylic acid (14.8 g), m.p. 175°C, is thus obtained. (2RS,4R)-2-(4-Dimethylaminophenyl)-4-25 thiazolidinecarboxylic acid may be prepared as in Example 34 SD, but starting from L-cysteine (21.2 g) ^ o ■ i 124 and 4-dimethylaminobenzaldehyde (27.5 g). (2RS,4R)-2-(4-dimethylaminophenyl)-4-thiazolidinecarboxylic acid (41.5 g), m.p. 184°C, used as it is in subsequent syntheses, is thus obtained.

Example 49 The operation is carried out in a fashion similar to that described in Example 41, but starting from 2-trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(3-pyridyl)-3-thiazolidinyl]-2-10 oxoethyl>ureido}benzoate (0.95 g) in 1M tetrabutylammonium fluoride solution (3.2 cc). The crude product is purified by chromatography on silica [eluent: ethyl acetate]. The fractions containing the expected product are combined and concentrated to 15 dryness under reduced pressure at 40°C. After vigorous stirring in diisopropyl ether, (2R,4R)—3—{3—{2—[4-tert-butoxycarbonyl-2-(3-pyridyl)-3-thiazolidinyl]-2-oxoethyl>ureido}benzoic acid (0.36 g), m.p. 147°C, is thus obtained ([c*]|° = +51.1° +1.7° (C = 0.49%; DMF)) 20 [proton NMR (200 MHz, DMSO D6, 6 in ppm), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 120°C: 7.3 to 7.6 (m, 5H, aromatic); 8.0 (bs, 1H, N-C6H*-C in position 2); 8.5 (bs, 1H, H in position 2 of pyridyl); 8.8 (bs, 1H, H in 25 position 6 of pyridyl). Infrared spectrum (KBr), 125 characteristic bands in cm"1: 3385, 2975, 2930, 2600, 2500, 1730, 1660, 1610, 1590, 1560, 1485, 1370, 1240, 1150, 760, 710, 685]. 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(3-pyridyl)-3-thiazolidinyl]-2-oxoethyl}ureido}benzoate may be prepared in a fashion similar to that described in Example 41 §A, but starting from tert-butyl (2RS,4R)-2-(3-pyridyl)-4-thiazolidinecarboxylate (2.0 g), 2-{3-[3-(2-trimethylsilylethoxycarbonyl)phenyl]ureido}acetic acid (2.5 g) and N,N'-dicyclohexylcarbodiimide (1.8 g). The crude product is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (40/60 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(3-pyridyl)-3-thiazolidinyl]-2-oxoethyl}ureido}benzoate (1.0 g) is thus obtained in the form of a yellow oil, used as it is in subsequent syntheses. tert-Butyl (2RS,4R)-2-(3-pyridyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 48 SB, but starting from tert-butyl (2RS,4R)-3-tert-butoxycarbonyl-2-(3-pyridyl)-4-thiazolidinecarboxylate 24 3 5 126 (3.4 g) and iodotrimethylsilane (1.7 cc). tert-Butyl (2RS,4R)-2-(3-pyridyl)-4-thiazolidinecarboxylate (2.1 g) is thus obtained in the form of a yellow oil, used as it is in subsequent syntheses. tert-Butyl (2RS,4R)-3-tert-butoxycarbonyl-2- ( 3-pyridyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 48 §C, but starting from (2RS,4R)-3-tert-butoxy-carbonyl-2-(3-pyridyl)-4-thiazolidinecarboxylic acid 10 (9.0 g), para-toluenesulphonyl chloride (5.7 g) and tert-butanol (2.2 g). The crude product obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (50/50 by volume)]. The fractions containing the expected product are combined and 15 concentrated to dryness under reduced pressure at 40°C. tert-Butyl (2RS,4R)-3-tert-butoxycarbonyl-2-(3-pyridyl)-4-thiazolidinecarboxylate (1.25 g) is thus obtained in the form of an orange oil, used as it is in subsequent syntheses. 20 (2RS,4R)-3-tert-Butoxycarbonyl-2-(3-pyridyl)- 4-thiazolidinecarboxylic acid may be prepared in a fashion similar to that described in Example 48 SD, but starting from (2RS,4R)-2-(3-pyridyl)-4-thiazolidine-carboxylic acid (26.5 g), IN sodium hydroxide solution 25 (130 cc) and di-tert-butyl dicarbonate (28.4 g). (2RS,4R)-3-tert-butoxycarbonyl-2-(3-pyridyl)-4-thiazolidinecarboxylic acid (31.6 g) is thus obtained h 1 4 i -rf V/ 127 in the form of a yellow amorphous powder, used as it is in subsequent syntheses. (2RS,4R)-2-(3-Pyridyl)-4-thiazolidinecarboxylic acid may be prepared as in Example 34 §D, 5 but starting from L-cysteine (25.0 g) and nicotinaldehyde (22 cc). (2RS,4R)-2-(3-Pyridyl)-4-thiazolidinecarboxylic acid (26.6 g), m.p. 149°C, used as it is in subsequent syntheses, is thus obtained.

Example 50 The operation is carried out in a fashion similar to that described in Example 39, but starting from ethyl (2R,4R)-3-{3-{3-[2-(4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido>phenyl}~ propionate (2.5 g) and lithium hydroxide (0.2 g). The 15 crude product is purified by chromatography on silica [eluent: ethyl acetate/methanol (90/10 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. (2R,4R)-3-{3-{3-[2-(4-tert-butoxycarbonyl-2-20 phenyl-3-thiazolidinyl)-2-oxoethyl]ureido}phenyl}- propionic acid (0.25 g) is thus obtained in the form of an amorphous beige solid ([a]" = +58.4° ±1.6° (C = 0.61 %; CHClj)) [proton NMR (200 MHz, DMSO D5, 6 in ppm), 2 rotamers at room temperature, characteristic 25 chemical shifts at 25#C: 1.5 (bs, 9H, (CH3)3); 2.5 (bt, 2H, CH2); 2.8 (bt, 2H, CH2); 6.8 (bd, 1H, N-C6H,-C 128 in position 4); 7.1 to 7.5 (m, 7H, aromatic); 7.7 (bd, 2H, aromatic). Infrared spectrum (KBr), characteristic bands in cm"1: 3380, 2975, 2930, 2620, 1730, 1645, 1610, 1590, 1555, 1490, 1370, 1235, 1150, 785, 730, 695].

Ethyl (2R,4R)-3-{3-{3-[2-(4-tert-butoxy-carbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]-ureido>phenyl}propionate may be prepared in a fashion similar to that described in Example 38, but starting from tert-butyl (2R,4R)-3-[2-(1-imidazolylcarboxamido)-acetyl]-2-phenyl-4-thiazolidinecarboxylate (3.75 g) and ethyl 3-(3-aminophenyl)propionate (3.5 g). The oily residue obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)] and the fractions containing the expected product are combined, then concentrated to dryness under reduced pressure at 40°C. Ethyl (2R,4R)-3-{3-(3-[2-(4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido>phenyl}propionate (2.5 g) is thus obtained in the form of an oil used as it is in subsequent syntheses.

Example 51 The operation is carried out in a fashion similar to that described in Example 39, but starting from ethyl (2Rf4R)-3-{3-[2-(4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido}-phenoxyacetate (2.4 g) and lithium hydroxide (0.2 g). 24 Zb 129 The crude product is purified by chromatography on silica [eluent: ethyl acetate]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. After vigorous stirring in diisopropyl ether, (2R,4R)- 3—{3—[2—(4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido}phenoxyacetic acid (1.3 g) is thus obtained in the form of an amorphous solid ([a]" = +63.7° ±1.2° (C = 0.96 %; CHC13) ) [proton NMR (200 MHz, DMSO D6/ 6 in ppm), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 120°C: 4.5 (bs, 2H, 0CH2C02); 6.5 (ddd, 1H, N-CgHj.-C in position 4); 6.9 (d, 1H aromatic); 7.1 to 7.7 (m, 7H, aromatic). Infrared spectrum (KBr), characteristic bands in cm"1: 3380, 2975, 2930, 2630, 2550, 1735, 1640, 1600, 1555, 1490, 1370, 1240, 1150, 770, 730, 695].

Ethyl (2R,4R)-3-{3-[2-(4-tert-butoxycarbonyl- 2-phenyl-3-thiazolidinyi)-2-oxoethyl]ureido}phenoxy-acetate may be prepared in a fashion similar to that described in Example 38, but starting from tert-butyl (2R,4R)-3- [ 2-(1-imidazolylcarboxamido)acetyl]-2-phenyl- 4-thiazolidinecarboxylate (4.4 g) and ethyl 3-aminophenoxyacetate (4.1 g). The oily residue obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (35/65 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced 130 pressure at 40°C. Ethyl (2R,4R)-3-{3-[2-(4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido>phenoxyacetate (2.5 g) is thus obtained in the form of an amorphous beige powder used as it is 5 in subsequent syntheses.

Example 52 Hydroxylamine hydrochloride (0.4 g) in solution in water (5 cc) is added to a solution of tert-butyl (2R,4R)-3-{2-[3-(3-acetylphenyl)-10 ureido]acetyl)-2-phenyl-4-thiazolidinecarboxylate (2.5 g) in methanol (10 cc) and pyridine (5 cc). The reaction mixture is stirred under reflux for 2 hours. After evaporation of the solvents under reduced pressure at 45°C the residue is taken up in ethyl 15 acetate (100 cc). The organic phase is washed with water (3 x 50 cc), dried over magnesium sulphate and concentrated to dryness under reduced pressure. The crude product obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (50/50 by 20 volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. After vigorous stirring in diisopropyl ether, tert-butyl (2R,4R)-3-{2-{3-[3-(1-hydroxyiminoethyl)-(E)-phenyl]ureido)acetyl}-2-phenyl-25 4-thiazolidinecarboxylate (0.5 g) is obtained in the form of an amorphous solid ([a]" = +54" ±1.5° 131 (C = 0.61 %; CHC13) ) [proton NMR (300 MHz, DMSO D6, S in ppm), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 120°C: 2.1 (s, 3H, CH3) ; 7.2 to 7.6 (m, 8H, aromatic); 7.7 (bs, 1H, 5 N-CgH^-C in position 2); 10.8 (bs, 1H, NOH). An NOE effect has been observed between the methyl group at 2.1 ppm and the NOH oxime group at 10.8 ppm. Infrared spectrum (KBr), characteristic bands in cm"1: 3350, 2975, 2930, 1740, 1650, 1610, 1590, 1560, 1370, 1240, 10 1150, 1005, 790, 730, 695]. tert-Butyl (2R,4R)-3-{2-[3-(3-acetylphenyl)-ureido]acetyl}-2-phenyl-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 38, but starting from tert-butyl (2R,4R)-3-[2-15 (1-imidazolylcarboxamido)acetyl]-2-phenyl-4- thiazolidinecarboxylate (3.75 g) and 3-aminoaceto-phenone (1.46 g). The oily residue obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (50/50 by volume)]. The fractions 20 containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. tert-Butyl (2R,4R)-3-{2-[3-(3-acetylphenyl)ureido]-acetyl}-2-phenyl-4-thiazolidinecarboxylate (2.5 g) is thus obtained in the form of an amorphous yellow powder 25 used as it is in subsequent syntheses. *"•> / 7 C £ i j 0 132 Example 53 The operation is carried out in a fashion similar to that described in Example 38, but starting from tert-butyl (2R,4R)-3-[2-(l-imidazolylcarboxamido) 5 acetyl]-2-phenyl-4-thiazolidinecarboxylate (2.3 g) and tetra-n-butylammonium 3-aminobenzylsulphonate (4.7 g). The crude product obtained is dissolved in acetone (20 cc) and a solution of potassium nonafluorobutane-sulphonate (1.86 g) in acetone (20 cc) is added. The 10 reaction mixture is stirred for 18 hours at a temperature in the vicinity of 25°C, followed by the addition of diisopropyl ether (80 cc). The insoluble product is separated by filtration, washed with a mixture of acetone and diisopropyl ether (30/70 by 15 volume) (2 x 3 cc). After vigorous stirring in acetonitrile, potassium (2R,4R)-3-{3-[2-(4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido}benzyl-sulphonate (0.75 g), m.p. 185°C is thus obtained ([a]" = +37.3° ±1.4° (C = 0.38 %; 20 CHC13)) [proton NMR (300 MHz, DMSO, D6# 6 in ppm), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 120°C: 3.7 (AB, 2H, CH2S03); 6.9 (bd, 1H, N-C6H<,-C in 6 position); 7.1 to 7.6 (m, 8H, aromatic). Infrared spectrum (KBr), 25 characteristic bands in cm"1: 3400, 2980, 2945, 1740, 1660, 1615, 1600, 1560, 1500, 1375, 1220, 1200, 1160, 1050, 800, 735, 700].

Tetra-n-butylammonium 3-aminobenzyl- 133 sulphonate may be prepared in a fashion similar to that described in Example 41 §G, but starting from tetra-n-butylammonium 3-nitrobenzylsulphonate (11.6 g) and 5 % palladium on charcoal (0.3 g). Tetra-n-butylammonium 3-5 aminobenzylsulphonate (10.5 g) is thus obtained in the form of an oil used as it is in subsequent syntheses.

Tetra-n-butylammonium 3-nitrobenzylsulphonate may be prepared as follows: sodium 3-nitrobenzylsulphonate (6.9 g) and then tetra-n-butyl-10 ammonium hydrogenosulphonate (9.9 g) are added to a 0.5M aqueous solution of potassium dihydrogen phosphate (800 cc). The mixture is extracted with methylene chloride (500 cc). The organic phase is dried over magnesium sulphate and concentrated to dryness under 15 reduced pressure at 40°C. Tetra-n-butylammonium 3-nitrobenzylsulphonate (13 g) is thus obtained in the form of an oil used as it is in subsequent syntheses.

Sodium 3-nitrobenzylsulphonate may be prepared according to the method described by PURGOTTI 20 and MONTI, Gazz. Chim. Ital. 30, II, 247.

Example 54 The operation is carried out in a fashion similar to that described in Example 39, but starting from methyl (RS)-2-{{3-[3-(2-(2R,4R)-4-tert-25 butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]-ureido>phenyl}propionate (1.5 g) and lithium hydroxide 134 (0.11 g). The crude product is purified by chromatography on silica [eluent: ethyl acetate]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. After vigorous stirring in diisopropyl ether, (RS)-2-{{3-[3-(2-(2R,4R)-4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido>-phenyl}propionic acid (0.25 g) is obtained in the form of an amorphous solid [proton NMR (200 MHz, DMSO D5, 6 in ppm), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 120°C: 1.4 (d, 3H, CH3) ; 3.5 (bm, 1H, Ph-CH-C02) ; 6.9 (bd, 1H, N-C6H<,-C in position 4); 7.1 to 7.4 (m, 6H, aromatic); 7.7 (bd, 2H, aromatic). Infrared spectrum (KBr), characteristic bands in cm"1: 3385, 2975, 2935, 1735, 1650, 1610, 1560, 1495, 1455, 1370, 1240, 1155, 785, 730, 700].

Methyl (RS)-2-{{3-[3-(2-(2R,4R)-4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl) -2-oxoethyl ] -ureido>phenyl}propionate may be prepared in a fashion similar to that described in Example 38, but starting from tert-butyl (2R,4R)-3-[2-(1-imidazolylcarboxamido)-acetyl]-2-phenyl-4-thiazolidinecarboxylate (3.75 g) and methyl (RS)-2-(3-aminophenyl)propionate (3.22 g). The oily residue obtained is purified by chromatography on silica gel [eluent: ethyl acetate] and the fractions containing the expected product are combined and j i\ : j 135 concentrated to dryness under reduced pressure at 40°C. Methyl (RS)-2-{{3-[3-(2-(2R,4R)-4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido}phenyl}-propionate (3.1 g) is thus obtained in the form of an 5 amorphous beige powder used as it is in subsequent syntheses.

Methyl (RS)-2-(3-aminophenyl)propionate may be prepared in a fashion similar to that described in Example 41 §G, but starting from methyl (RS)—3~(3— 10 nitrophenyl)propionate (4 g) and 5 % palladium on charcoal (4.3 g). Methyl (RS)-2-(3-aminophenyl)-propionate (3.3 g) is thus obtained in the form of an oil used as it is in subsequent syntheses.

Methyl (RS)-3-(3-nitrophenyl)propionate may 15 be prepared as follows: gaseous hydrochloric acid is bubbled for 3 hours through a solution of (RS)-2-(3-nitrophenyl)propionitrile (5 g) in methanol (40 cc). The mixture obtained is stirred under reflux for 30 minutes, and the insoluble product is separated by 20 filtration. The filtrate is concentrated to dryness under reduced pressure at 40°C. The crude product is purified by chromatography on silica [eluent: petroleum ether/ethyl acetate (80/20 by volume)]. The fractions containing the expected product are combined and 25 concentrated to dryness under reduced pressure at 40#C. Methyl (RS)-3-(3-nitrophenyl)propionate (4 g) is thus obtained in the form of an oil used as it is in 136 subsequent syntheses.

(RS)-2-(3-Nitrophenyl)propionitrile may be prepared according to the method described by E. Felder et al., J. Med. Chem., 13, 559 (1970).

Example 55 By proceeding in a fashion similar to that described in Example 41 §A, but starting from tert-butyl (2R,4R)-2-(4-fluorophenyl)-4-thiazolidinecarboxylate (1.7 g) in solution in anhydrous aceto-10 nitrile (20 cc), N,N'-dicyclohexylcarbodiimide (1.24 g) and 2-(2-indolylcarboxamido)acetic acid (1.3 g) in a mixture of anhydrous acetonitrile (40 cc) and dichloromethane (40 cc), after recrystallisation in diisopropyl ether, tert-butyl (2R,4R)-2-(4-fluorophenyl)-3-[2-(2-15 indolylcarboxamido)acetyl]-4-thiazolidinecarboxylate (1.7 g), m.p. 176°C, is obtained. 2-(2-Indolylcarboxamido)acetic acid may be obtained according to the method described by J. R. JOHNSON et al., J. Am. Chem. Soc., 69, 2370 (1947).

Example 56 By proceeding in a fashion similar to that described in Example 1, but starting from (2RS,5SR)-N-methyl-N-phenyl-5-phenylprolinamide (1.2 g), 2-[3-(3-methylphenyl)ureido]acetic acid (0.94 g) in suspension 25 in 1,2-dichloroethane (25 cc) and sulphinyl chloride (0.33 cc), after recrystallisation in acetonitrile, 137 (2RS, 5SR)-N-methyl-1-[3-(3-methylphenyl)ureidoacetyl]-N-phenyl-5-phenylprolinamide (1 g), m.p. 210°C, is obtained. (2RS,5SR)-N-Methyl-N-phenyl-5-phenyl-prolinamide may be prepared in a fashion similar to that described in Example 25 §A, but starting from (2RS, 5SR)-1-(tert-butoxycarbonyl-N-methyl-N-phenyl-5-phenylprolinamide (2.2 g) in anhydrous chloroform (25 cc) and iodotrimethylsilane (0.85 cc). (2RS,5SR)-N-Methyl-N-phenyl-5-phenylprolinamide (1.2 g) is obtained in the form of an orange oil, used as it is in the subsequent syntheses.

A (2RS,5SR)-1-(tert-Butoxycarbonyl)-N-methyl-N-phenyl-5-phenylprolinamide may be prepared as follows: at a temperature in the vicinity of 0°C a solution of N,N'-dicyclohexylcarbodiimide (2.1 g) in anhydrous acetonitrile (15 cc) is added dropwise to a suspension of (2RS,5SR)-1-(tert-butoxycarbonyl)-5-phenylproline (2.9 g) and N-methylaniline (1.1 cc) in anhydrous acetonitrile (25 cc). The reaction mixture is stirred for 30 minutes at a temperature in the vicinity of 0°C, then for 20 hours at a temperature in the vicinity of 20°C. The insoluble product is then separated by filtration and washed with dichloromethane (2 x 20 cc). The filtrate is concentrated to dryness without reduced pressure at a temperature in the vicinity of 40°C. The product obtained is purified by chromatography on silica [eluent: 138 dichloromethane/methanol (99/1 by volume)]. The fractions containing the expected product are combined, then concentrated to dryness under reduced pressure. After recrystallisation in pentane, (2RS,5SR)-1-(tert-butoxycarbonyl )-N-methyl-N-phenyl-5-phenylprolinamide (2.2 g), m.p. 132°C, is thus obtained.

Example 57 By proceeding in a fashion similar to that described in Example 1, but starting from (2RS,5SR)-5-phenyl-(1,2,3,4-tetrahydro-l-quinolyl)-2-carbonyl-pyrrolidine (3 g), 2-[3-(3-methylphenyl)ureido]acetic acid (2 g) in suspension in 1,2-dichloroethane (100 cc) and sulphinyl chloride (0.7 cc), after recrystallisation in acetonitrile, (2RS,5SR)-l-{2-[3-(3-methylphenyl)ureido]acetyl}-5-phenyl(1,2,3,4-tetrahydro-l-quinolyl)-2-carbonylpyrrolidine (1.5 g), m.p. 158°C, is obtained. (2RS,5SR)-5-Phenyl-(1,2,3,4-tetrahydro-1-quinolyl)-2-carbonylpyrrolidine may be prepared in a fashion similar to that described in Example 25 §A, but starting from (2RS,5SR)-l-(tert-butoxycarbonyl)-5-phenyl-(1,2,3,4-tetrahydro-l-quinolyl)-2-carbonyl-pyrrolidine (4.1 g) in anhydrous chloroform (50 cc) and iodotrimethylsilane (1.4 cc). (2RS,5SR)-5-phenyl-(1,2,3,4-tetrahydro-l-quinolyl)-2-carbonylpyrrolidine (3 g) is obtained in the form of an orange oil used as it is in subsequent syntheses. 139 (2RS,5SR)-1-(tert-Butoxycarbonyl)-5-phenyl-(1,2,3,4-tetrahydro-l-quinolyl)-2-carbonylpyrrolidine may be prepared in a fashion similar to that described in Example 56 §A but starting from (2RS,5SR)-l-(tert-butoxycarbonyl ) -5-phenylproline (8.7 g), 1,2,3,4-tetra-hydroguinoline (3.8 cc) in anhydrous acetonitrile (75 cc) and N,N'-dicylohexylcarbodiimide (6.2 g) in anhydrous acetonitrile (45 cc). After crystallisation in hexane, (2RS,5SR)-l-(tert-butoxycarbonyl)-5-phenyl-(1,2,3,4-tetrahydro-l-quinolyl)-2-carbonylpyrrolidine (4.1 g), m.p. 132°C, is obtained.

Example 58 By proceeding in a fashion similar to that described in Example 1, but starting from (2RS,5SR)-3,3-dimethylpiperidino-2-carbonyl-5-phenylpyrrolidine (1.8 g), 2-[3-(3-methylphenyl)ureido]acetic acid (1.3 g) in 1,2-dichloroethane (75 cc), and sulphinyl chloride (0.5 cc), after recrystallisation in acetonitrile, (2RS,5SR)-3,3-dimethylpiperidino)-2-carbonyl-l--{2-[3- (3-methylphenyl)ureido]acetyl}-5-phenylpyrrolidine (0.7 g), m.p. 150°C, is obtained. (2RS,5SR)-3,3-dimethylpiperidino-2-carbonyl-5-phenylpyrrolidine may be prepared in a fashion similar to that described in Exampale 25 §A, but starting from l-tert-butoxycarbonyl-3,3-dimethyl-piperidino-2-carbonyl-5-phenylpyrrolidine (5.0 g) in anhydrous chloroform (50 cc) and iodotrimethylsilane (1.9 cc). After recrystallisation in diisopropyl ether, (2RS,5SR)-(3,3-dimethylpiperidino)-2-carbony1-5-phenylpyrrolidine (1.8 g) , m.p. 163°C, is obtained. (2RS,5SR)-1-(tert-butoxycarbonyl)—(3,3— 5 dimethylpiperidino)-2-carbonyl-5-phenylpyrrolidine may be prepared in a fashion similar to that described in Example 56 §A, but starting from (2RS,5SR)-1-(tert-butoxycarbony1)-5-phenylproline (5.8 g), 3,3-dimethylpiperidine (2.6 cc) in anhydrous acetonitrile (50 cc) and N,N'-10 dicyclohexylcarbodiimide (4.1 g) in anhydrous acetonitrile (30 cc). After recrystallisation in hexane, (2RS,5SR)-1-(tert-butoxycarbonyl)-(3,3-dimethylpiperidino)-2-carbonyl-5-phenylpyrrolidine (4 g), m.p. 110°C, is obtained.

Example 59 By proceeding in a fashion similar to that described in Example 2, but starting from (2RS,5SR)-1-(2-aminoacetyl)-5-phenyl-N-tert-butylprolinamide (1.9 g) in solution in anhydrous tetrahydrofuran (20 cc) and 3-methylphenyl isocyanate (0.82 cc), after recrystallisation 20 in acetonitrile, (2RS,5SR)-N-tert-butyl-l-[3-(3- methylphenyl)ureidoacetyl]-5-phenylprolinamide (0.7 g), m.p. 169°C, is obtained. (2RS,5SR)-1-(2-Aminoacetyl)-5-phenyl-N-tert-butylprolinamide may be prepared in a fashion similar to 25 that described in Example 2 §A, but starting from (2RS,5SR)-l-(2-tert-butoxycarbonylaminoacetyl)-N-tert- 141 butyl-5-phenylprolinamide (2.7 g) in solution in anhydrous chloroform (50 cc) and iodotrimethylsilane (0.95 cc). (2RS,5SR)-l-(2-aminoacetyl)-5-phenyl-N-tert-butylprolinamide (1.9 g) is obtained in the form of an amorphous powder used as it is in subsequent syntheses.

Proton NMR (250 MHz, DMSO D6, S in ppm), 2 rotamers at room temperature, 1.35 (s, 9H, C(CH3)3)/ 1.8 to 2.4 (bm, 4H, CH2-CH2) ; 2.7, 3.25 and 3.8 (d, 2H, AB, CH2C02); 4.45 (bm, 1H, CHN); 5.1 (bm, 1H, CHN); 7.2 to 8 (m, 6H, aromatic and NH). 1-(2-tert-Butoxycarbonylaminoacetyl)-N-tert-butyl-5-phenylprolinamide may be prepared in a fashion similar to that described in Example 2 §B, but starting from (2RS,5SR)-N-tert-butyl-5-phenylprolinamide (1.8 g), 2-tert-butoxycarbonylaminoacetic acid (1.28 g) in anhydrous acetonitrile (50 cc) and N,N'-dicyclohexylcarbodiimide (1.5 g) in anhydrous acetonitrile (25 cc). After crystallisation in petroleum ether, 1-(2-tert-butoxycarbonylaminoacetyl)-N-tert-butyl-5-phenylprolinamide (2.7 g), m.p. 1170C, is obtained. (2RS,5SR)-N-tert-Butyl-5-phenylprolinamide may be prepared in a fashion similar to that described in Example 25 §A, but starting from (2RS,5SR)-l-(tert-butoxycarbonyl)-N-tert-butyl-5-phenylprolinamide (3.5 g) in anhydrous chloroform (50 cc) and iodotrimethylsilane (2.1 cc). (2RS,5SR)-N-tert-butyl-5-phenyl-prolinamide (1.8 g) is obtained in the form of a yellow oil used as it is in subsequent syntheses. 142 (2RS,5 SR) — 1-tert-butoxycarbony1-N-tert-butyl-5-phenylprolinamide may be obtained as follows: at a temperature in the vicinity of 20°C, N,N'-carbonyl-diimidazole (1.8 g) is added to a solution of (2RS,5SR)-l-tert-butoxycarbonyl-5-phenylproline (2.9 g) in 1,2-dichloroethane (50 cc). The reaction mixture is stirred for 2 hours at a temperature in the vicinity of 20°C, then tert-butylamine (1 cc) is added and the mixture is heated under reflux for 5 hours while stirring. After cooling, the reaction mixture is diluted with dichloromethane (100 cc) and washed successively with a normal aqueous hydrochloric acid solution (2 x 50 cc), then with water (3 x 50 cc). The organic phase is dried over magnesium sulphate, then evaporated to dryness under reduced pressure. The residue obtained is purified by chroma-tography on silica [eluent: dichloromethane/methanol (97.5/2.5 by volume)] and the fractions containing the expected product are combined and concentrated to dryness under reduced pressure. (2RS,5SR)-1-tert-Butoxycarbonyl-N-tert-butylphenylprolinamide (3 g) is thus obtained in the form of a yellow oil used as it is in subsequent syntheses.

Example 60 By proceeding in a fashion similar to that described in Example 9, but starting from methyl cis-3-<3—(2—(2,5-diphenyl-l-pyrrolidinyl)-2-oxoethyl]- 143 ureido}phenylacetate (10.6 g) in solution in methanol (150 cc) and potassium hydroxide (1.7 g) dissolved in water (30 cc) and after treatment and recrystallisation in ethanol, cis-3-{3-[2-(2,5-diphenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}phenylacetic acid (1.2 g), m.p. 152°C, is obtained.

Methyl cis-3—-{3—[2-(2,5-diphenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}phenylacetate may be prepared in a fashion similar to that described in Example 41 §A, but starting from cis-2,5-diphenylpyrrolidine (4.45 g), 2-[3-(3-methoxycarbonylmethyl-phenyl)ureido]acetic acid (5.32 g) and N,N'-dicyclo-hexylcarbodiimide (4.2 g) in acetonitrile (40 cc).

After treatment, methyl cis-3-{3-[2~(2,5-diphenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}phenylacetate (10.6 g) is obtained in the form of an oil used as it is in subsequent syntheses. 2—[3—(3-Methoxycarbonylmethylphenyl)ureido]-acetic acid may be prepared in a fashion similar to that described in Example 1 §A, but starting from glycine (9.42 g), potassium carbonate (34.69 g) in water (220 cc) and methyl 3-isocyanatophenylacetate (24 g) dissolved in 1,4-dioxane (170 cc). After treatment and recrystallisation in ethyl acetate, 2-[3-(3-methoxycarbonylmethylphenyl)ureido]acetic acid (46.85 g), m.p. 136°C, is obtained. 144 Example 61 By proceeding in a fashion similar to that described in Example 9; but starting from ethyl cis-3-{3-{3-[2-(2,5-diphenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}-phenyl}propionate (4.8 g) in solution in methanol (25 cc) and potassium hydroxide (0.25 g) dissolved in water (5 cc) and after treatment, cis-3-{3—< 3—[2-(2,5-diphenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}phenyl}propionic acid (0.9 g), m.p. 170°C, is obtained.

Ethyl cis-3-{3-[2-(2,5-diphenyl-l-pyrrolidinyl) -2-oxoethyl ]ureido}phenyl}propionate may be prepared in a fashion similar to that described in Example 41 §A, but starting from cis-2,5-diphenyl-pyrrolidine (0.68 g), 2-{3-[3-(2-ethoxycarbonylethyl)-phenyl}ureido}acetic acid (0.9 g) and N,N'-dicyclo-hexylcarbodiimide (0.63 g) in acetonitrile (6 cc).

After treatment, ethyl cis-3-{3-[2-(2,5-diphenyl-l-pyrrolidinyl )-2-oxoethyl]ureido}phenyl}propionate (1.8 g) is obtained in the form of an oil used as it is in subsequent syntheses. 2-{3-[3-(2-Ethoxycarbonylethyl)phenyl]-ureido}acetic acid may be prepared in a fashion similar to that described in Example 1 §A, but starting from glycine (0.44 g), potassium carbonate (1.63 g) in water (10 cc) and ethyl 3-(3-isocyanatophenyl)propionate 24 35 145 (1.3 g) in solution in 1,4-dioxane (8 cc). After treatment, 2-{3-[3-(2-ethoxycarbonylethyl)phenyl]-ureido)acetic acid (0.9 g) is obtained in the form of an amorphous solid used as it is in subsequent syntheses.

Ethyl 3-(3-isocyanatophenyl)propionate may be prepared as follows: in the space of 30 minutes at a temperature in the vicinity of -20°C a solution of bis(trichloromethyl) carbonate (2.36 g) in toluene (20 cc) is added to a suspension of charcoal (0.45 g) in ethyl 3-(3-aminophenyl)propionate (3 g) solution in toluene (60 cc). The reaction mixture is heated at a temperature in the vicinity of 110°C for 2 hours and 30 minutes, cooled to a temperature in the vicinity of 20°C, filtered over Celite and concentrated under reduced pressure. Ethyl 3-(3-isocyanatophenyl)-propionate is thus obtained in the form of an oil used as it is in subsequent syntheses.

Example 62 By proceeding in a fashion similar to that described in Example 9, but starting from methyl (2RS,5SR)-3-{3-{2-[2-(2-methoxyphenyl)-5-phenyl-l-pyrrolidinyl]-2-oxoethyl>ureido}phenylacetate (1.2 g) in solution in methanol (20 cc) and potassium hydroxide (0.19 g) in solution in water (4 cc), and after treatment and recrystallisation in diethyl ether, 146 (2RS,5SR)-3-{3-{2-[2-(2-methoxyphenyl)-5-phenyl-l-pyrrolidinyl]-2-oxoethyl>ureido}phenylacetic acid (0.6 g), m.p. 140°C, is obtained.

Methyl cis-3-{3-{2-[2-(2-methoxyphenyl)-5-phenyl-l-pyrrolidinyl]-2-oxoethyl>ureido}phenylacetate may be prepared in a fashion similar to that described in Example 41 §A, but starting from (2RS,5SR)-2-(2-methoxyphenyl)-5-phenyl-pyrrolidine (0.57 g) , 2—[3—(3— methoxycarbonylmethylphenyl)-ureido]acetic acid (0.6 g) and N,N'-dicyclohexylcarbo-diimide (0.46 g) in acetonitrile (4.5 cc). After treatment, methyl (2RS,5SR)-3-{3-(2-[2-(2-methoxyphenyl)-5-phenyl-l-pyrrolidinyl]-2-oxoethyl}ureido}phenylacetate (1.2 g) is obtained in the form of an oil used as it is in subsequent syntheses.

A - (2RS,5SR)-2-(2-methoxyphenyl)-5-phenyl-pyrrolidine may be prepared as follows: a 1.6M solution (12.8 cc) of butyllithium in hexane is added dropwise at a temperature in the vicinity of -78°C while stirring to a solution of N-benzyl-o-methoxybenzaldimine (2.25 g) in tetrahydrofuran (20 cc). After returning to a temperature in the vicinity of 20°C, stirring is continued for 40 hours, then the reaction mixture is poured into a saturated aqueous solution of ammonium chloride (100 cc) and the product is extracted with diisopropyl ether (50 cc, then with 2 x 25 cc). The combined organic phases are 147 dried over magnesium sulphate and concentrated to dryness under reduced pressure at a temperature in the vicinity of 35°C. The residue is dissolved in a normal aqueous hydrochloric acid solution (25 cc) and the solution is heated under reflux for 1 minute. After cooling to a temperature in the vicinity of 20°C, the solution is washed with diisopropyl ether (3 x 25 cc), then the pH is adjusted to 9 using an N aqueous sodium hydroxide solution and the product is extracted with diisopropyl ether (3 x 25 cc). The organic extracts are combined, washed with water (2 x 25 cc), dried over magnesium sulphate and concentrated to dryness under reduced pressure at a temperature in the vicinity of 35°C. The product obtained is purified by chromatography on silica (eluent: petroleum ether/diisopropyl ether (50/50 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at a temperature in the vicinity of 45°C. (2RS,5SR)-2-(2-Methoxyphenyl)-5-phenylpyrrolidine (0.9 g) is thus obtained in the form of an amorphous solid used as it is in subsequent syntheses.

B - N-Benzyl-o-methoxybenzaldimine may be prepared as follows: a solution of ortho-methoxybenzal-dehyde (60 cc), benzylamine (55 cc) and para-toluene-sulphonic acid (50 mg) in toluene (150 cc) is heated for three hours under reflux while collecting the water formed using a Dean-Stark apparatus. After returning to 148 a temperature in the vicinity of 20 °C, the organic phase is washed with a saturated aqueous sodium bicarbonate solution (100 cc), then with water (100 cc), dried over magnesium sulphate and 5 concentrated under reduced pressure. After distillation, N-benzyl-o-methoxybenzaldimine (57.3 g) distilling in the range from 155 to 159°C at a pressure of 130 Pa, is obtained.

Example 63 By proceeding in a fashion similar to that described in Example 9, but starting from methyl (2RS,5SR)-3-{3-{2-[2-(3-hydroxyphenyl)-5-phenyl-l-pyrrolidinyl]-2-oxoethyl}ureido}phenylacetate (0.46 g) in solution in methanol (10 cc) and potassium hydroxide 15 (0.1 g) in solution in water (2 cc), and after treatment and recrystallisation in ethanol, (2RS,5SR)-3-{3-{2-[2-(3-hydroxyphenyl)-5-phenyl-l-pyrrolidinyl]-2-oxoethyl}ureido}phenylacetic acid (0.2 g), m.p. 166°C, is obtained.

Methyl (2RS,5SR)-3-{3-{2-[2-(3-hydroxy- phenyl)-5-phenyl-l-pyrrolidinyl]-2-oxoethyl}-ureido}phenylacetate may be prepared in a fashion similar to that described in Example 41 §A, but starting from (2RS,5SR)-2-(3-hydroxyphenyl)-5-phenyl-25 pyrrolidine (0.48 g), 2-[3-(3-methoxycarbonylmethyl-phenyl)ureido]acetic acid (0.54 g) and N,N'-dicyclo- 149 hexylcarbodiimide (0.42 g) in acetonitrile (5 cc).

After treatment, methyl (2RS,5SR)-3-{3-{2-[2-(3-hydroxypheny1)-5-phenyl-1 -pyrro1idiny1]-2-oxoethyl}-ureido}phenylacetate (0.73 g) is obtained in the form of a meringue-like product used as it is in subsequent syntheses. (2RS,5SR)-2-(3-Hydroxyphenyl)-5-phenyl-pyrrolidine may be prepared in a fashion similar to that described in Example 62 §A, but starting from N-benzyl-m-hydroxybenzaldimine (4.22 g) in solution in tetrahydrofuran (40 cc) and a 2.5M solution (33.6 cc) of butyllithium in hexane. After treatment, (2RS,5SR)-2-(3-hydroxyphenyl)-5-phenylpyrrolidine (3.3 g) is obtained in the form of an oil used as it is in subsequent syntheses.

N-Benzyl-m-hydroxybenzaldimine may be prepared in a fashion similar to that described in Example 62 §A, but starting from 3-hydroxybenzaldehyde (61.1 g) and benzylamine (55 cc) in toluene (450 cc). After treatment, N-benzyl-m-hydroxybenzaldimine (100.3 g), m.p. 151°C, is obtained.

Example 64 By proceeding in a fashion similar to that described in Example 9, but starting from benzyl cis-4-{3-[2-(2,5-diphenyl-1-pyrrolidinyl)-2-oxoethyl]-ureido}phenylacetate (4 g) in solution in methanol 150 (65 cc) and potassium hydroxide (0.61 g) in solution in water (12 cc), and after treatment, cis-4-{3-[2-(2,5-diphenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}phenylacetic acid (1.8 g), m.p. 221°C, is obtained [proton NMR (200 5 MHz, DMSO D6, 6 in ppm), 1.4 to 2.4 (m, 4H, CH2-CH2); 3.3 (s, 2H, CH2C02); 3.2 and 3.8 (ABX, 2H, CH2NH) ; 5.1 (m, 2H, 2 CHN); 6.1 (t, 1H exchangeable, NH); 6.9 (d, 2H, aromatic in para position); 7.1 to 7.4 (m, 12H, aromatic); 8.6 (s, 1H exchangeable, NH)], [infrared 10 spectrum (KBr), characteristic bands in cm"1 3375, 3095, 3070, 3035, 2980, 2880, 1735, 1700, 1630, 1610, 1515, 1450, 1560, 805, 760, 705].

Benzyl cis-4-{3-[2-(2,5-diphenyl-l-pyrrolidinyl) -2-oxoethyl ]ureido}phenylacetate may be 15 prepared in a fashion similar to that described in Example 41 §A, but starting from cis-2,5-diphenylpyrrolidine (1.7 g), 2-[3-(4-benzyloxycarbonylmethyl-phenyl)ureido]acetic acid (2.6 g) and N,N'-dicyclo-hexylcarbodiimide (1.6 g) in acetonitrile (15 cc). 20 After treatment, benzyl cis-4-{3-[2-(2,5-diphenyl-l-pyrrolidinyl) -2-oxoethyl ]ureido}phenylacetate (4 g) is obtained in the form of a meringue-like product used as it is in subsequent syntheses. 2-[3-(4-Benzyloxycarbonylmethylphenyl)-25 ureido]acetic acid may be prepared in a fashion similar to that described in Example 1 §A, but starting from glycine (3.68 g), sodium bicarbonate (4.1 g) in water (150 cc) and benzyl 4-isocyanatophenylacetate (13 g) in r* * i 151 solution in 1,4-dioxane (60 cc). After treatment, 2 — [3 — (4-benzyloxycarbonylmethylphenyl)ureido]acetic acid (5.2 g), m.p. 192°C, is obtained.

A - Benzyl 4-isocyanatophenylacetate may be 5 prepared as follows: in the space of 15 minutes at a temperature in the vicinity of -25°C, a solution of benzyl 4-aminophenylacetate (11.8 g) in toluene (150 cc) is added to a suspension of charcoal (1 g) in a mixture of trichloromethyl chloroformate (5.9 cc) and 10 toluene (50 cc). The reaction mixture is stirrred at a temperature in the vicinity of 25°C for two hours, then heated at a temperature in the vicinity of 110°C for 2 hours. After cooling to a temperature in the vicinity of 25°C, the reaction mixture is degassed by bubbling 15 through nitrogen, filtered on filter paper and concentrated under reduced pressure at a temperature in the vicinity of 52°C. Benzyl 4-isocyanatophenylacetate (15.4 g) is thus obtained in the form of an oil used as it is in subsequent syntheses.

Benzyl 4-aminophenylacetate may be prepared according to the method described by E. ZURABYAN et al., Izv. Akad. Nauk. SSSR, Ser. Khim., (11) 2036 (1964) .

Example 65 By proceeding in a fashion similar to that described in Example 9, but starting from methyl 152 (2RS,5SR)-3-{3-{2-[2-(2-methylphenyl)-5-phenyl-l-pyrrolidinyl ]-2-oxoethyl>ureido}phenvlacetate (3.5 g) in solution in methanol (60 cc) and potassium hydroxide (0.56 g) in solution in water (11 cc), and after treatment and recrystallisation in ethyl acetate, (2RS,5SR)-3-{3-{2-[2-(2-methylphenyl)-5-phenyl-l-pyrrolidinyl ]-2-oxoethyl}ureido}phenylacetic acid (2.2 g), m.p. 133°C, is obtained.

Methyl (2RS,5SR)-3-{3-{2-[2-(2-methylphenyl)-5-phenyl-l-pyrrolidinyl]-2-oxoethyl}ureido}phenyl-acetate may be prepared in a fashion similar to that described in Example 41 §A, but starting from (2RS,5SR)-2-(2-methylphenyl)-5-phenylpyrrolidine (1.6 g), 2 — [3—(3-methoxycarbonylmethylphenyl)ureido]-acetic acid (1.8 g) and N,N'-dicyclohexylcarbodiimide (1.4 g) in acetonitrile (15 cc). After treatment, methyl (2RS/5SR)-3-{3-{2-[2-(2-methylphenyl)-5-phenyl-l-pyrrolidinyl]-2-oxoethyl}ureido}phenylacetate (3.5 g) is obtained in the form of a meringue-like product used as it is in subsequent syntheses. (2RS,5SR)-2-(2-Methylphenyl)-5-phenylpyrrolidine may be prepared in a fashion similar to that described in Example 62 §A, but starting from N-benzyl-o-methylbenzaldimine (4.18 g) in solution in tetrahydrofuran (40 cc) and a 2.5M solution (25.6 cc) of butyllithium in hexane. After treatment, (2RS,5SR)- 153 2-(2-methylphenyl)-5-phenylpyrrolidine (1.7 g) is obtained in the form of an oil used as it is in subsequent syntheses.

N-Benzyl-o-methylbenzaldimine may be prepared according to the method described by A. PADVA et al., J. Amer. Chem. Soc., 91 2653 (1969).

Example 66 By proceeding in a fashion similar to that described in Example 9, but starting from ethyl (2RS,5SR) -3-{3-(2-[2-(3-hydroxyphenyl)-5-(3-methoxyphenyl )-1-pyrrolidinyl]-2-oxoethyl}ureido}benzoate (1.8 g) in solution in methanol (30 cc) and potassium hydroxide (0.29 g) in solution in water (6 cc) and after treatment and recrystallisation in diethyl ether, (2R*,5S*)-3-{3-{2-[2-(3-hydroxyphenyl)-5-(3-methoxyphenyl )-1-pyrrolidinyl]-2-oxoethyl}ureido}benzoic acid (1 g), m.p. 172°C, is obtained.

Ethyl (2RS,5SR)-3-{3-{2-[2-(3-hydroxypheny1)-5-(3-methoxyphenyl)-1-pyrrolidinyl]-2-oxoethyl}-ureido}benzoate may be prepared in a fashion similar to that described in Example 41 §A, but starting from (2RS,5SR)-2-(3-hydroxyphenyl)-5-(3-methoxyphenyl)-pyrrolidine (1.3 g), 2-[3-(3-ethoxycarbonylphenyl)-ureido]acetic acid (1.3 g) and N,N'-dicyclohexylcarbo-diimide (1 g) in acetonitrile (11 cc). After treatment, 154 ethyl (2RS,5SR)-3-{3-{2-[2-(3-hydroxyphenyl)-5-(3-methoxyphenyl)-1-pyrrolidinyl]-2-oxoethyl}ureido}-benzoate (1.8 g) is obtained in the form of a meringuelike product used as it is in subsequent syntheses. (2RS,5SR)-2-(3-Hydroxyphenyl)-5-(3-methoxyphenyl ) pyrrolidine may be prepared in a fashion similar to that described in Example 62 §A, but starting from N-[(3-hydroxyphenyl)methylene](3-methoxyphenyl) -methylamine (7.2 g) in tetrahydrofuran (60 cc) and a 2.5M solution (50.4 cc) of butyllithium in hexane.

After treatment, (2RS,5SR)-2-(3-hydroxyphenyl)-5-( 3-methoxy-phenyl)pyrrolidine (4.5 g) is obtained in the form of an oil used as it is in subsequent syntheses. N-[(3-hydroxyphenyl)methylene](3- methoxyphenyl)methylamine may be prepared in a fashion similar to that described in Example 62 §B, but starting from 3-hydroxybenzal-dehyde (13.2 g) and m-methoxybenzylamine (13.7 g) in toluene (90 cc). After treatment N-[(3-hydroxyphenyl)-methylene](3-methoxyphenyl ) methylamine (20.7 g), m.p. 103°C, is obtained. 2 —[3 —(3-Ethoxycarbonylphenyl)ureido]acetic acid may be prepared as described in Example 1 SA, but starting from glycine (9.85 g) , sodium bicarbonate (11 g) in solution in water (150 cc), and ethyl 3-isocyanatobenzoate (25 g). After treatment, 2—[3—(3— ethoxycarbonylphenyl)ureido]acetic acid (16 g), m.p. 174°C, is obtained. 155 Example 67 By proceeding in a fashion similar to that described in Example 9, but starting from benzyl (2RS, 5SR)-4-{3-{2-[2-(3-hydroxyphenyl)-5-phenyl-l-pyrrolidinyl ]-2-oxoethyl}ureido}phenylacetate (1.8 g) in solution in methanol (30 cc) and potassium hydroxide (0.27 g) in solution in water (6 cc), and after treatment and crystallisation in diethyl ether, (2RS,5SR)-4-{3-{2-[2(3-hydroxyphenyl)-5-phenyl-l-pyrrolidinyl ]-2-oxoethyl}ureido}phenylacetic acid (0.5 g), m.p. 260°C, is obtained.

Benzyl (2RS,5SR)-4-{3-{2-[2-(3-hydroxyphenyl )-5-phenyl-l-pyrrolidinyl]-2-oxoethyl}-ureido}phenylacetate may be prepared in a fashion similar to that described in Example 41 §A, but starting from (2RS,5SR)-2-(3-hydroxyphenyl)-5-phenyl-pyrrolidine (1.4 g), 2-[3-(3-methoxycarbonylmethyl-phenyl)ureido]acetic acid (2.0 g) and N,N'-dicyclo-hexylcarbodiimide (1.2 g) in acetonitrile (11 cc).

After treatment, benzyl (2RS,5SR)-4-{3-{2-[2-(3-hydroxyphenyl)-5-phenyl-l-pyrrolidinyl]-2-oxoethyl}-ureido}phenylacetate (1.8 g) is obtained in the form of a meringue-like product used as it is in subsequent syntheses. 156 Example 68 By proceeding in a fashion similar to that described in Example 9, but starting from tert-butyl cis-{4-{3-[2-(2,5-diphenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}-phenylthio}acetate (1.3 g) in solution in methanol (20 cc) and potassium hydroxide (0.17 g) in solution in water (4 cc), and after treatment, cis-{4-{3-[2-(2,5-diphenyl-l-pyrrolidinyl)-2-oxoethyl]ureido>phenylthio}-acetic acid (0.5 g), m.p. about 200°C, is obtained [proton NMR (200 MHz, DMSO D6, 6 in ppm), 1.8 to 2.4 (m, 4H, CH2-CH2) ; 3.35 (s, 2H, CH2S); 3.3 and 3.85 (ABX, 2H, CH2N): 5.1 (m, 2H, 2 CHN); 6.5 (t, 1H exchangeable, NH); 7.1 to 7.4 (m, 14H, aromatic); 9 (s, 1H exchangeable, NH)], [infrared spectrum (KBr), characteristic bands in cm"1 3400, 3090, 3060, 3030, 2975, 2875, 1640, 1595, 1540, 1495, 1450, 1400, 825, 760, 700]. tert-Butyl cis-{4-{3-[2-(2,5-diphenyl-l-pyrrolidinyl )-2-oxoethyl]ureido}phenylthio}acetate may be prepared in a fashion similar to that described in Example 41 §A, but starting from 2,5-diphenyl-pyrrolidine (0.46 g), 2-[3-(4-tert-butoxycarbonyl-methylthiophenyl)ureido]-acetic acid (0.7 g) and N,N'-dicyclohexylcarbodiimide (0.42 g) in acetonitrile (5 cc). After treatment, tert-butyl cis-{4-{3-[2-(2,5-diphenyl-1-pyrrolidinyl)-2-oxoethyl]ureido}phenyl- 157 thio}acetate (1.3 g) is obtained in the form of a meringue-like product used as it is in subsequent syntheses. 2-[3-(4-tert-Butoxycarbonylmethylthiophenyl)-ureido]acetic acid may be prepared in a fashion similar to that described in Example 1 §A, but starting from glycine (0.65 g), potassium carbonate (2.4 g) in water (15 cc) and tert-butyl (4-isocyanatophenylthio)acetate (2.3 g) in 1,4-dioxane (12 cc). After treatment, 2-[3-(4-tert-butoxycarbonylmethylthiophenyl)ureido]acetic acid (1.7 g) is obtained in the form of a meringue-like -product used as it is in subsequent syntheses. tert-Butyl (4-isocyanatophenylthio)acetate may be prepared in a fashion similar to that described in Example 64 §A, but starting from tert-butyl (4-aminophenylthio)acetate (3.1 g) in toluene (117 cc), charcoal (0.26 g) and trichloromethyl chloroformate (1.56 cc) in toluene (30 cc). After treatment, tert-butyl (4-isocyanatophenylthio)acetate (2.3 g) is obtained in the form of an oil used as it is in subsequent syntheses. tert-Butyl (4-aminophenylthio)acetate may be prepared in a fashion similar to that described in Example 17 for the preparation of ethyl (3-aminophenyl-thio)acetate, but starting from 4-aminothiophenol (5 g) and tert-butyl bromoacetate (6.4 cc) in ethanol (80 cc). tert-Butyl (4-aminophenylthio)acetate (7.45 g) 158 is thus obtained in the form of an oil used as it is in subsequent syntheses.

Example 69 By proceeding in a fashion similar to that described in Example 9, but starting from ethyl (2RS,5SR)-3-{3-(2-[2-( 2-hydroxyphenyl) -5-phenyl-l-pyrrolidinyl ]-2-oxoethyl}ureido}benzoate (0.8 g) in solution in methanol (15 cc) and potassium hydroxide (0.27 g) in solution in water (3 cc), and after treatment and recrystallisation in diisopropyl ether, (2RS,5SR)-3-{3-{2-[2-(2-hydroxypheny1)-5-phenyl-1-pyrrolidinyl]-2-oxoethyl}ureido}benzoic acid (0.21 g), m.p. about 160°C, is obtained [proton NMR (200 MHz, DMSO D6, S in ppm), 1.8 to 2.5 (2m, 4H, CH2-CH2); 3.3 and 4 (ABX, 2H, CH2N) ; 5.2 (m, 2H, 2 CHN); 6.7 to 7.4 (m, 13H, aromatic); 6.8 (bt 9(s) 9.8(bs) 12.8(vbs) (4H exchangeable, 1 OH, 1 C02H and 2 NH)], [Infrared spectrum (KBr), characteristic bands in cm"1 3400, 3070, 2980, 1695, 1630, 1560, 1490, 1460, 760, 700, 685].

Ethyl (2RS,5SR) —3—{3—-{2— [2-(2-hydroxyphenyl)-5-phenyl-l-pyrrolidinyl]-2-oxoethyl}ureido}benzoate may be prepared in a fashion similar to that described in Example 41 SA, but starting from (2RS,5SR)-2-(2-hydroxyphenyl)-5-phenylpyrrolidine (0.5 g), 2—[3—(3— ethoxycarbonylphenyl)ureido]acetic acid (0.56 g) and N,N'-dicyclohexylcarbodiimide (0.43 g) in acetonitrile 159 (7.5 cc). After treatment, ethyl (2RS,5SR)-3-{3-{2-[2-(hydroxyphenyl)-5-phenyl-l-pyrrolidinyl]-2-oxoethyl}ureido}benzoate (0.85 g) is obtained in the form of a meringue-like product used as it is in subsequent syntheses. (2RS,5SR)-2-(2-Hydroxyphenyl)-5-phenyl-pyrrolidine may be prepared as follows: in the space of ten minutes at a temperature in the vicinity of -78°C, a 2.5M solution of butyllithium (24 cc) is added to a solution of diisopropylamine (8.6 cc) in tetrahydrofuran (60 cc). The reaction mixture is then stirred at a temperature in the vicinity of 20°C for fifteen minutes, then cooled to a temperature in the vicinity of -70°C. In the space of five minutes at a temperature in the vicinity of -70°C, a solution of N-benzyl-o-hydroxy-benzaldimine (4.2 g) in tetrahydrofuran (5 cc) is then added. The solution is stirred for ten minutes at a temperature in the vicinity of -7 0°C, then left to warm up to a temperature of 20°C. The reaction mixture is then saturated by bubbling through ethylene for 40 hours, then poured into a saturated aqueous solution of ammonium chloride (150 cc), and the product is extracted with ethyl ether (1 x 100 cc, then 2 x 50 cc). The combined organic phases are dried over magnesium sulphate and concentrated to dryness under reduced pressure at a temperature in the vicinity of 35°C. The residue is dissolved in a normal aqueous 160 hydrochloric acid solution (150 cc) and the solution is heated under reflux for 1 minute. After cooling to a temperature in the vicinity of 20 °C, the solution is washed with ethyl ether (3 x 100 cc), then the pH is adjusted to 11 using a 4N aqueous sodium hydroxide solution, and the product is extracted with ethyl ether (3 x 75 cc). The organic extracts are combined, washed with water (2 x 50 cc), dried over magnesium sulphate and concentrated to dryness under reduced pressure at a temperature in the vicinity of 35°C. The product obtained is purified by chromatography on silica [eluent: dichloromethane, then dichloromethane/methanol (95/5 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at a temperature in the vicinity of 45°C. (2RS,5SR)-2-(2-hydroxyphenyl)-5-phenylpyrrolidine (0.5 g) is thus obtained in the form of an oil used as it is in subsequent syntheses.

N-Benzyl-o-hydroxybenzaldimine may be prepared in a fashion similar to that described in Example 62 §B, but starting from 2-hydroxybenzaldehyde (21.2 cc) and benzylamine (22 cc) in toluene (180 cc). After treatment, N-benzyl-o-hydroxybenzaldimine (38.2 g) is obtained in the form of a solid melting at below 50"C. 161 Example 70 By proceeding in a fashion similar to that described in Example 9, but starting from methyl ( 2RS,5SR)-3-{3-{2-[2-(2-hydroxyphenyl)-5-phenyl-l-pyrrolidinyl ]-2-oxoethyl>ureido}phenylacetate (1.4 g) in solution in methanol (30 cc) and potassium hydroxide (0.49 g) in solution in water (6 cc), and after treatment and recrystallisation in diisopropyl ether, (2RS,5SR)-3-{3-{2-[2-(2-hydroxyphenyl)-5-phenyl-l-pyrrolidinyl ]-2-oxoethyl>ureido}phenylacetic acid (0.45 g), m.p. about 165°C, is obtained.

Methyl (2RS,5SR)-3-{3-{2-[2-(2-hydroxy-phenyl)-5-phenyl-l-pyrrolidinyl]-2-oxoethyl}-ureido}phenylacetate may be prepared in a fashion similar to that described in Example 41 §A, but starting from (2RS,5SR)-2-(3-hydroxyphenyl)-5-phenyl-pyrrolidine (1.8 g), 2-[3-(3-methoxycarbonylmethyl-phenyl)ureido]acetic acid (2 g) and N,N'-dicyclohexyl-carbodiimide (1.55 g) in acetonitrile (30 cc). After treatment, methyl (2RS,5SR)-3-{3-{2-[2-(2-hydroxyphenyl )-5-phenyl-l-pyrrolidinyl]-2-oxoethyl>-ureido}phenylacetate (1.4 g) is obtained in the form of a meringue-like product used as it is in subsequent syntheses. ' / i *t 162 Example 71 The operation is carried out in a fashion similar to that described in Example 41, but starting from 2-trimethylsilylethyl (2S,5R)-3-{3-{2-[2-tert-5 butoxycarbonyl-5-(3-indolyl)-1-pyrrolidinyl]-2- oxoethyl>ureido}benzoate (0.2 g) and a 1M solution of tetrabutylammonium fluoride (1.0 cc). The crude product is dissolved in ethyl acetate (25 cc) and extracted with a 0.IN aqueous sodium hydroxide solution 10 (2 x 5 cc). The aqueous phases are brought to a pH of 2 by addition of a IN aqueous hydrochloric acid solution. ' The product precipitated is separated by filtration, washed with distilled water (2 x 5 cc) and dried in air. (2S,5R)-3-{3-{2-[2-tert-butoxycarbonyl-5-(3-15 indolyl)-1-pyrrolidinyl]-2-oxoethyl}ureido}benzoic acid (0.12 g) is thus obtained in the form of a solid melting at 160°C, [a]§° = +10.7° ±1.1° (C= 0.43 %; CH3OH) , [proton NMR (300 MHz, DMSO D6, 5 in ppm, J in Hz): 1.5 (s, 9H,-C(CH3)3; 1.8 to 2.5 (m, 4H, -CH2=-CH2-); 20 3.6 and 4.1 (2dd, J = 17.5 and 5.1, 2H, N-CO-CH2-N); 4.26 (dd, J = 9 and 8, 1H, N-CH-COO-); 5.52 (d, J = 8.5, 1H, N-CH-Ar); 6.38 (t, J = 5, 1H, -NH-C0-); 7.0 to 7.7 (m, 7H, aromatic); 7.68 (s, 1H, N-CH=); 8 (bs, 1H in position 2 on NH-Ph-COO); 9.03 (broad, 25 1H, Ph-NH-CO-); 11.05 (broad, 1H, -NH-), an NOE effect has been observed between the N-CH= of indole and the proton in position 5 of pyrrolidine], [infrared 163 spectrum (KBr), characteristic bands in cm"1: 3380, 2980, 2935, 2700 to 2250 (broad band), 1720 to 1695 (broadband), 1635, 1595, 1560, 1490, 1460, 1370, 1155 745, 685]. 2-Trimethylsilylethyl (2S,5R) — 3—{3— <2—[2-tert-butoxycarbonyl-5-(3-indolyl)-1-pyrrolidinyl]-2-oxoethyl}ureido}benzoate may be prepared in a fashion similar to that described in Example 41 §A, but starting from tert-butyl (2S,5RS)-5-(3-indolyl)-2-pyrrolidinecarboxylate (0.5 g), 2-{3-[3-(2-trimethyl-silylethoxycarbonyl)phenyl]ureido}acetic acid (0.59 g) and N,N'-dicyclohexvlcarbodiimide (0.36 g). After initial chromatography on silica [eluent: ethyl acetate/cyclohexane (40/60 by volume)], the fractions containing the mixture of the diastereoisomers are concentrated to dryness under reduced pressure at 40°C and the residue obtained is purified in a second chromatographic operation on silica [eluent ethyl acetate/ cyclohexane (with an ethyl acetate gradient)] The fractions containing each of the two diastereoisomers are combined and concentrated to dryness under reduced pressure at 40°C. 2-Trimethylsilylethyl (2S,5R)—3—{3—<2—[4-tert-butoxycarbonyl-5-(3-indolyl)-1-pyrrolidinyl]-2-oxoethyl>ureido}benzoate (0.20 g) (first elution product) and 2-trimethylsilylethyl (2S,5S)-3-{3-{2-[4-tert-butoxycarbonyl-5-(3-indolyl)-1-pyrrolidinyl]-2- 164 oxoethyl}ureido}benzoate (0.26 g) (second elution product) are thus obtained. tert-Butyl (2S,5RS)-5-(3-indolyl)-2-pyrrolidinecarboxylate may be prepared in a fashion similar to that described in Example 48 §B, but starting from tert-butyl (2S,5R)-l-tert-butoxycarbonyl-5-(3-indolyl)-2-pyrrolidinecarboxylate (0.7 g) and iodotrimethylsilane (0.25 cc). tert-Butyl (2S,5RS)-5-(3-indolyl)-5-pyrrolidinecarboxylate (0.50 g) is thus obtained in the form of an oil used as it is in subsequent syntheses. tert-Butyl (2S,5R)-l-tert-butoxycarbonyl-5-(3-indolyl)-2-pyrrolidinecarboxylate may be prepared as follows: a solution of indole (3.5 g) in methylene chloride (30 cc) is added to a solution of tert-butyl (2S,5RS)-l-tert-butyoxycarbonyl-5-methoxy-2-pyrrolidinecarboxylate (10.0 g) and para-toluene-sulphonic acid (0.6 g) in anhydrous methylene chloride (100 cc), cooled to a temperature in the vicinity of 5°C. At the end of the addition, the reaction mixture is brought to a temperature in the vicinity of 25°C, stirred for 2 hours at that temperature, then hydrolysed by addition of a saturated aqueous sodium bicarbonate solution (40 cc). The organic phase is decanted and the aqueous phase is extracted with methylene chloride (2 x 50 cc). The organic phases are combined, dried over magnesium sulphate and 165 concentrated to dryness under reduced pressure at 30°C. The residue obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (10/90 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 35°C. After vigorous stirring in diisopropyl ether, tert-butyl (2S,5R)-1-tert-butoxycarbonyl-5-(3-indolyl)-2-pyrrolidinecarboxylate (1.2 g) (first elution product), m.p. 214°C and tert-butyl (2S,5S)-l-tert-butoxycarbonyl-5-(3-indolyl)-2-pyrrolidinecarboxylate (0.8 g) (second elution product), m.p. 194°C, are thus obtained.

Example 72 The operation is carried out in a fashion similar to that described in Example 41, but starting from 2-trimethylsilylethyl (2S,5S)-3-{3-{2~[2-tert-butoxycarbonyl-5-(3-indolyl)-1-pyrrolidinyl]-2-oxoethyl>ureido}benzoate (0.25 g) and a 1M solution of tetrabutylammonium fluoride. The crude product is dissolved in ethyl acetate (25 cc) and extracted with 0.1N aqueous sodium hydroxide solution (2 x 10 cc). The aqueous phases are brought to a pH of 2 by addition of a IN aqueous hydrochloric acid solution. The product precipitated is separated by filtration, washed with distilled water (2 x 5 cc) and dried in air. (2S,5S)-3-{3-{2-[2-tert-butoxycarbonyl-5-(3-indolyl)-1- 166 pyrrolidinyl]-2-oxoethyl}ureido}benzoic acid (0.09 g) is thus obtained in the form of an amorphous product, [a}f = -42.9° ±1.5° (C = 0.503 %; CH30H), [proton NMR (300 MHz, DMSO D6, 5 in ppm, J in Hz); 1.44 (s, 5 9H, -C(CH3)3; 1.7 to 2.4 (m, 4H, -CH2-CH2-); 3.59 and 3.99 (2dd, J = 18 and 6, 2H, N-CO-CH2-N); 4.55 (d, J = 9 Hz, 1H, N-CH-COO-); 5.53 (d( J = 8, 1H, N-CH-Ar); 6.3 (t, J = 6.1 Hz, 1H, -NH-CO-); 6.9 to 7.6 (m, 7H, aromatic); 7.15 (bs, 1H, N-CH=); 7.94 (broad s, 1H, in 10 position 2 on NH-Ph-COO); 8.95 (broad, 1H, Ph-NH-CO-)? 11.02 (broad, 1H, -NH-), 12.75 (broad, 1H, COOH). Two NOE effects have been observed between N-CH= of indole and the protons in positions 2 and 5 of pyrrolidine], [infrared spectrum (KBr), characteristic bands in cm"1: 15 3385, 2975, 2930, 2700 to 2250 (broad band), 1730, 1690, 1640, 1560, 1490, 1460, 1395, 1370, 1155, 740, 685].

Example 73 The operation is carried out in a fashion 20 similar to that described in Example 38, but starting from tert-butyl (2R,4R)-3-[2-(1-imidazolylcarboxamido)-acetyl]-2-phenyl-4-thiazolidinecarboxylate (4.84 g) and tetra-n-butylammonium (RS)-1-(3-aminophenyl)ethane-sulphonate (8.85 g). A solution of potassium nona-25 fluorobutanesulphonate (2.5 g) in acetone (15 cc) is added to the crude product obtained, in the form of the 167 tetra-n-butylammonium salt, dissolved in acetone (20 cc). After stirring for 2 hours at a temperature in the vicinity of 25°C, diisopropyl ether (220 cc) is added. The insoluble product is separated by 5 filtration, washed with a mixture of acetone and diisopropyl ether (30/70 by volume) (2 x 3 cc) and purified by chromatography on silica [eluent: ethyl acetate/methanol (85/15 by volume)]. The fractions containing the expected product are combined and 10 concentrated to dryness under reduced pressure at 40°C. After vigorous stirring in acetonitrile, potassium (RS)-l-{3-{-3[2~(2R,4R)-4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido]-phenyl}ethane-sulphonate (0.40 g) (mixture of the A and B forms), 15 m.p. 240°C, is thus obtained in the form of a solid ([a]g° = +50.1° ±1.5' (C = 0.57 %; CH30H), [proton NMR (200 MHz, DMSO D6 + several drops of CD3COOD, & in ppm, J in Hz), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 20 120°C: 1.51 (m, 12H, -C(CH3)3 and CH3); 3.28 and 3.45 (2dd, J = 12.5 and 6, 2H, S-CH2-); 3.7 (m, 2H, -CH- and 1H of N-COCH2-N); 4.05 (d, J = 17, 1H, the other H of N-COCH2-N); 5.0 (t, J = 6, 1H, N-CH-COO); 6.4 (s, 1H, S-CH-N); 6.97 (broad d, J = 8, 1H, in position 4 on C0-25 NH-Ph); 7.08 (t, J = 8, 1H, in position 5 on CO-NH-Ph); 7.2 to 7.5 (m, 5H, aromatic); 7.64 (bd, J = 8, 2H, aromatic)] [Infrared spectrum (KBr), characteristic ,514 bands in cm'1: 3370, 2970, 2920, 2870, 1725, 1655, 1610, 1590, 1555, 1490, 1450, 1365, 1205, 1150, 1025, 725, 695].

Tetra-n-butylammonium (RS)-l-(3-aminophenyl)ethanesulphonate may be prepared in a fashion 5 similar to that described in Example 41 §G, but starting from tetra-n-butylammonium (RS)-1-(3-nitro-phenyl)ethanesulphonate (22.4 g) and palladized charcoal (0.8 g/5 %). Tetra-n-butylammonium l-(3-amino-phenyl)ethanesulphonate (20.7 g) is thus obtained in the 10 form of an oil used as it is in subsequent syntheses.

Tetra-n-butylammonium (RS)-1-(3-nitro-phenyl)ethanesulphonate may be prepared as follows: 3-(i-bromoethyl)-5-nitrobenzene (11.5 g) is added to a solution of sodium sulphite (9.45 g) in distilled water (125 cc). 15 The reaction mixture is heated for 3 hours at a temperature in the vicinity of 70°C, cooled to a temperature in the vicinity of 25°C then transferred into 0.5M aqueous potassium dihydrogen phosphate solution (1450 cc). Tetra-n-butylammonium hydrogen sulphate (17.8 g) is then added and 20 the mixture is extracted with methylene chloride (300 cc). The organic phase is washed successively with water (3 x 300 cc) and with a saturated aqueous sodium chloride solution (3 00 cc), dried over magnesium sulphate and concentrated to dryness under reduced pressure at 40°C. 25 Tetra-n-butylammonium (RS)-1-(3-nitrophenyl)ethane- 169 sulphonate (22.4 g) is thus obtained in the form of an oil used as it is in subsequent syntheses.

(RS)-3-(1-bromoethyl)nitrobenzene may be prepared according to the method described by E. FELDER 5 et al., J. Med. Chem., 13, 559 (1970).

Example 74 The operation is carried out in a fashion similar to that described in Example 38, but starting from tert-butyl (2R,4R) 3-[2-(1-imidazolylcarboxamido)-10 acetyl]-2-phenyl-4-thiazolidinecarboxylate (2.42 g) and 1-(3-aminophenyl)ethanol (1.4 g). The crude product is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (75/25 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure. After recrystallisation in acetonitrile, tert-butyl (2R,4R)-3-{2-{3-[(RS)-3-(1-hydroxyethyl)phenyl]ureido>acetyl}- 2-phenyl-4-thiazolidinecarboxylate (0.62 g) (mixture of the A and B forms), m.p. 160°C, is thus obtained ([a]" = +60.7° ±1.3° (C = 0.51 %; DMF), [proton NMR (200 MHz, plus several drops of CD3COOD, S in ppm, J in Hz), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 120°C: 1.35 (d, J = 6.5, 3H, -CH3); 1.5 (s, 9H, -C(CH3)3; 3.29 and 25 3.45 (2dd, J = 12.5 and 6, 2H, S-CH2-); 3.72 (bd, 1H of N-C0CH2-N); 4.06 (d, J = 17, 1H, the other H of 170 N-C0CH2-N); 4.68 (q, J = 6.5, 1H, -CH-0-); .0 (t, J = 6, 1H, N-CH-COO); 6.4 (s, 1H, S-CH-N); 6.93 (broad d, J = 8, 1H, in position 4 on CO-NH-Ph); 7.14 (t, J = 8, 1H, in position 5 on CO-NH-Ph); 7.22 (dd, J = 3 and 2.5, 1H, in position 2 on CO-NH-Ph); 7.2 to 7.5 (m, 4H, aromatic); 7.64 (bd, J = 8, 2H, aromatic)], [infrared spectrum (KBr), characteristic bands in cm"1: 3350, 2975, 2930, 1740, 1660, 1615, 1590, 1560, 1480, 1445, 1365, 1155, 1060, 730, 705, 700].

Example 75 The operation is carried out in a fashion similar to that described in Example 34, but starting from tert-butyl (2R,4R) 3-(2-aminoacetyl)-2-phenyl-4-thiazolidinecarboxylate (2.0 g) and 4-chloro-3-trifluoromethylphenyl isocyanate (1.6 g). The crude product obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. After vigorous stirring in hexane (20 cc), tert-butyl (2R,4R)-3-{2-[3-(4-chloro-3-tri-fluoromethylphenyl)ureido]acetyl}-2-phenyl-4-thiazolidinecarboxylate (0.7 g) is thus obtained in the form of an amorphous powder, ([a]" - +58.2° ±1.3° (C = 0.49 %; CH30H), [proton NMR (250 MHz, DMSO D6/ 6 in ppm, J in Hz), 2 rotamers at room temperature, peak coalescence at 130°C, characteristic chemical shifts at 24 3 5 1 4 111 130°C: 1.53 (s, 9H, -C(CH3)3); 3.29 and 3.47 (2dd, £ J = 12.5 and 6.5, 2H, S-CH2-); 3.73 (broad, 1H, of N-C0CH2-N); 4.10 (dd, J = 17.5 and 4, 1H, the other H of N-C0CH2-N); 5.0 (broad, 1H, N-CH-COO); 6.33 (broad, 1H, 5 -NHCO-); 6.4 (s, 1H, S-CH-N); 7.2 to 7.8 (m, 7H, aromatic); 7.97 (bs, 1H, in position 2 on CO-NH-Ph); 8.98 (broad, 1H, -CO-NH-Ph), [infrared spectrum (KBr), characteristic bands in cm"1: 3375, 2980, 2930, 2875, 1740, 1640, 1595, 1550, 1485, 1455, 1370, 1325, 1175, 10 1150, 895, 730, 695].

Example 76 The operation is carried out in a fashion similar to that described in Example 41, but starting from 2-trimethylsilylethyl (2R,4R)-3-{3-(2-[4-tert-15 butoxycarbonyl-2-(2-methylphenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}benzoate (1.37 g) and 1M tetrabutyl-ammonium fluoride solution (4.6 cc). The crude product is dissolved in a saturated sodium bicarbonate solution (25 cc) and washed with ethyl acetate (25 cc). The 20 aqueous phase is brought to a pH of 2 by addition of a 4N aqueous hydrochloric acid solution. The product precipitated is separated by filtration, washed with distilled water until the washing water becomes neutral, and dried in air. (2R,4R)-3-{2-{2-[4-tert-25 butoxycarbonyl-2-(2-methylphenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}benzoic acid (0.89 g) is thus obtained r W " ,, ' /-> L 4 ,■ J - i* 172 in the form of a solid, m.p. 152°C ([a]" = +70.3° ±1.9° (C = 0.53 %; DMF), [proton NMR (200 MHz, DMSO D6 plus several drops of CD3C00D, & in ppm, J in Hz), 2 rotamers at room temperature, peak coalescence at 110°C, 5 characteristic chemical shifts at 110°C: 1.56, (s, 9H, -C(CH3)3); 2.42 (s, 3H, Ar-CH3); 3.28 and 3.48 (2dd, J = 12 and 6.5, 2H, S-CH2-); 3.65 (broad, 1H of N-C0CHz-N); 4.05 (d, J = 17.5, 1H, the other H of N-COCH2-N-); 4.98 (t, J = 6.5, 1H, N-CH-COO); 6.24 (broad, 1H, -NH-10 CO-); 6.46 (s, 1H, S-CH-N); 7.10 to 7.65 (m, 5H, aromatic); 7.33 (t, J = 8, 1H, in position 5 on CO-NH-Ph); 7.94 (broad, 1H, in position 6 on S-CH-Ph); 8.0 (dd, 3=2 and 3, 1H, in position 2 on CO-NH-Ph); 8.67 (broad, 1H, -CO-NH-Ph)], [infrared spectrum (KBr), 15 characteristic bands in cm"1: 3380, 2980, 2935, 2700 to 2250 (wide band), 1715 to 1695 (wide band), 1655, 1610, 1595, 1560, 1490, 1370, 1155, 760, 745, 685]. 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(2-methylphenyl)-3-20 thiazolidinyl]-2-oxoethyl>ureido}benzoate may be prepared in a fashion similar to that described in Example 41 §A, but starting from tert-butyl (2RS,4R)-2-(2-methylphenyl)-4-thiazolidinecarboxylate (2.1 g), 2-{3-[3-(2-trimethylsilylethoxycarbonyl)-25 phenyl]ureido}acetic acid (2.5 g) and N,N'- dicyclohexyl-carbodiimide (1.6 g). The crude product is purified by chromatography on silica [eluent: ethyl 173 acetate/cyclohexane (40/60 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. 2-Trimethylsilylethyl (2R,4R)-3-{2-{2-[4-tert-butoxy-carbonyl-2-(2-methylphenyl)-3-thiazolidinyl]-1-oxoethyl>ureido}benzoate (1.7 g) is thus obtained in the form of an amorphous solid used as it is in subsequent syntheses. tert-Butyl (2RS,4R)-2-(2-methylphenyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 34 §C, but starting from (2RS,4R)-2-(2-methylphenyl)-4-thiazolidinecarboxylic acid (10.0 g) in solution in chloroform (130 cc), concentrated sulphuric acid (3.0 cc) and an excess of isobutene. The crude product obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (10/90 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. tert-Butyl (2RS,4R)-2-(2-methylphenyl ) -4-thiazolidinecarboxylate (3.8 g) is thus obtained in the form of an oil, a mixture of the (2R,4R) and (2S,4R) isomers, used as it is in subsequent syntheses. (2RS,4R)-2-(2-methylphenyl)-4-thiazolidinecarboxylic acid may be prepared as in Example 34 §D, but starting from L-cysteine (12.5 g) and 2-methyl- 2 i 1 4 174 benzaldehyde (12.0 cc). (2RS,4R)-2-(2-methylphenyl)-4-thiazolidinecarboxylic acid (18.4 g), m.p. 167°C, used as it is in subsequent syntheses, is thus obtained.

Example 77 At a temperature in the vicinity of 25°C potassium hydroxide (0.12 g) is added to a solution of methyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl}-10 ureido}phenylacetate (0.95 g) in a water/methanol (30/70 by volume) mixture (6 cc). The reaction mixture is stirred for 3 hours at a temperature in the vicinity of 25°C then concentrated to about half under reduced pressure. The solution obtained is diluted with water 15 (40 cc), washed with ethyl ether (2 x 30 cc), then brought to a pH of 2 by addition of a IN aqueous sulphuric acid solution (2.1 cc). The insoluble product is separated by filtration and purified by chromatography on silica [eluent: ethyl acetate/ 20 methanol (90/10 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. The amorphous product thus obtained (0.26 g) is dissolved in a IN aqueous sodium hydroxide solution. This solution is 25 filtered, then acidified by addition of a IN aqueous sulphuric acid solution. The product thus precipitated 175 is separated by filtration, washed with water (3 x 10 cc), then dried in air. (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}phenylacetic acid (0.26 g) , m.p. 110°C, is thus obtained ([a]" = +51.1° +1.6° (C = 0.528 %; DMF), [proton NMR (200 MHz, DMSO D6 plus several drops of CD3COOD, S in ppm, J in Hz), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 120°C: 1.55 (s, 9H, -C(CH3)3) ; 3.34 and 3.52 (2dd, J = 12.5 and 6.5, 2H, S-CH2-); 3.51 (s, 2H, ArCH2COO-); 3.8 and 4.07 (2d, J = 17.5, 2H, N-C0CH2-N); 5.02 (t, J = 6.5, N-CH-COO); 6.55 (s, 1H, S-CH-N); 6.85 (bd, J = 8, 1H, in position 4 on CO-NH-Ph); 7.05 to 7.4 (m, 6H, aromatic); 7.93 (bt, J = 8.5, 1H, in position 6 on S-CH-Ph-)], [infrared spectrum (KBr), characteristic bands in cm"1: 3380, 2980, 2930, 2700 to 2250 (broad band), 1735, 1650, 1615, 1595, 1560, 1490, 1460, 1370, 1230, 1155, 760, 705].

Methyl (2R,4R)-3-{3-(2-[4-tert-butoxy-carbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}phenylacetate may be prepared in a fashion similar to that described in Example 41 SA, but starting from tert-butyl (2RS,4R)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (1.46 g), 2-{3-[3-(methoxy-carbonylmethy1)phenyl]ureido)acetic acid (1.37 g) and N,N'-dicyclohexylcarbodiimide (1.15 g). The crude 176 product is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (50/50 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. Methyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}phenylacetate (0.95 g) is thus obtained in the form of an amorphous solid, used as it is in subsequent syntheses.

Example 78 The operation is carried out in a fashion similar to that described in Example 77, but starting from methyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(2-methoxyphenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}-phenylacetate (0.76 g) in a water/methanol (30/70 by volume) mixture (6 cc) and potassium hydroxide (0.09 g). The crude product (0.45 g) is dissolved in a 0.1N aqueous sodium hydroxide solution (7.5 cc). The solution thus obtained is washed with diethyl ether (2 x 10 cc), brought to a pH of 2 by addition of a IN aqueous sulphuric acid solution, then extracted with ethyl acetate (2 x 20 cc). The organic phases are combined/ dried over magnesium sulphate and concentrated to dryness under reduced pressure at 40#C. After vigorous stirring in diisopropyl ether, (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-{2-methoxyphenyl)-3- 177 thiazolidinyl]-2-oxoethyl>ureido}phenylacetic acid (0.25 g) is thus obtained in the form of an amorphous product ([q]d° = +6.4° ±1.0° (C = 0.466 %; CHC13), [proton NMR (200 MHz, DMSO D6 plus several drops of CD3COOD, & in ppm, J in Hz), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 120°C: 1.55 (s, 9H, -C(CH3)3); 3.22 and 3.45 (2dd, J = 12.5 and 7, 2H, S-CH2-); 3.51 (s, 2H, ArCH2C00-); 3.65 (bd, 1H of N-C0CH2-N) ; 3.93 (s, 3H, -OCH3); 4.05 (d, J = 17.5, 1H, the other H of N-COCH2-N); 4.91 (t, J = 7, 1H, N-CH-COO); 6.5 (s, 1H, S-CH-N); 6.85 (bd, J =8, 1H, in position 4 on CO-NH-Ph); 6.9 to 7.4 (m, 6H, aromatic); 7.9 (bd, J = 8, 1H, in position 6 on S-CH-Ph-)], [infrared spectrum (KBr), characteristic bands in cm"1: 3390, 2975, 2930, 2840, 2700 to 2250 (broad band), 1735, 1645, 1610, 1600, 1595, 1560, 1495, 1370, 1245, 1155, 1025, 760, 705].

Methyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl^^ 2-methoxyphenyl )-3-thiazolidinyl]-2-oxoethyl}ureido}phenylacetate may be prepared in a fashion similar to that described in Example 41 §A, but starting from tert-butyl (2RS,4R)-2-(2-methoxyphenyl-4-thiazolidinecarboxylate (1.9 g), 2-{3-[3-methoxycarbonylmethylphenyl]ureido)acetic acid (1.73 g) and N,N'-dicyclohexylcarbodiimide (1.4 g). The crude product is purified by chromatography on silica 178 [eluent: ethyl acetate/cyclohexane (50/50 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. Methyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(2-methoxyphenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}phenylacetate (1.5 g) is thus obtained in the form of an amorphous white solid, used as it is in subsequent syntheses. tert-Butyl (2RS,4R)-2-(2-methoxyphenyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 34 §C, but starting from (2RS,4R)-2-(2-methoxyphenyl)-4-thiazolidinecarboxylic acid (3.5 g) in solution in chloroform (50 cc), concentrated sulphuric acid (1.0 cc) and an excess of isobutene. The crude product obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. tert-Butyl (2RS,4R)-2-(2-methoxyphenyl)-4-thiazolidinecarboxylate (2.0 g) is thus obtained in the form of an oil, a mixture of the (2R,4R) and (2S,4R) isomers, used as it is in subsequent syntheses. /. "t 179 {2RS,4R)-2-(2-methoxyphenyl)-4-thiazolidinecarboxylic acid may be prepared as in Example 34 §D, but starting from L-cysteine (7.26 g) and 2-methoxybenzaldehyde (8.9 g). (2RS,4R)-2-(2-methoxyphenyl)-4-thiazolidine-5 carboxylic acid (3.7 g), m.p. 170°C, used as it is in subsequent syntheses, is thus obtained.

Example 79 The operation is carried out in a fashion similar to that described in Example 77, but starting from methyl 10 (RS)-3-{3-{2-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}-mandelate (0.70 g) in a water/methanol (30/70 by volume) mixture (7 cc) and potassium hydroxide (0.08 g). The crude product (0.45 g) is dissolved in a 0.1N 15 aqueous sodium hydroxide solution (8.5 cc). The solution thus obtained is washed with ethyl acetate (2 x 25 cc), filtered and acidified to a pH of 2 by addition of a IN aqueous hydrochloric acid solution.

The product precipitated is separated by filtration, washed with water (2 x 10 cc) and dried in air. (RS)-3-{3-{2-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}-mandelic acid (0.15 g) is thus obtained in the form of a white product, m.p. 135#C [proton NMR (200 MHz, DMSO 25 D6 plus several drops of CD3COOD, 6 in ppm, J in Hz), 180 2 rotamers at room temperature, peak coalescence at 110°C: characteristic chemical shifts at 110°C. 1.55 (s, 9H,-C(CH3)3); 3.32 and 3.53 (2dd, J = 12.5 and 6.5, 2H, S-CH2-); 3.8 (bd, 1H of N-C0CH2-N); 4.08 (d, J = 17.5, 1H, the other H of N-C0CH2-N); 5 (m and s, 2H in total respectively N-CH-COO and Ar-CH-); 6.2 (broad, 1H, -NHCO-); 6.54 (s, 1H, S-CH-N); 7.02 (bd, J = 7.5, 1H, in position 4 on CO-NH-Ph); 7.1 to 7.5 (m, 6H, aromatic); 7.94 (dd, J = 7.5 and 9, 1H, in position 6 on S-CH-Ph-); 8,5 (broad, -CONH-Ar)], [infrared spectrum (KBr), characteristic bands in cm"1: 3390, 2980, 2930, 2840, 2700 to 2250 (broad band), 1735, 1650, 1610, 1560, 1490, 1455, 1370, 1230, 1150, 1060, 790, 760, 700].

Methyl (2R,4R)-3-{3-{2-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl)ureido}mandelate may be prepared in a fashion similar to that described in Example 38, but starting from tert-butyl (2R,4R)-3-[2-(1-imidazolylcarboxamido)-acetyl]-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (3.2 g) and methyl (RS)-3-aminomandelate (2.7 g). The crude product is purified by two successive chromatographic operations on silica [eluent: methylene chloride/methanol (95/5 by volume) for the first chromatographic operation; eluent: ethyl acetate for the second chromatographic operation]. The fractions containing the expected product are combined and 181 concentrated to dryness under reduced pressure. Methyl (RS)—3—{3—<2—[(2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}-mandelate (1.6 g) is thus obtained in the form of a 5 meringue-like product, used as it is in subsequent syntheses. tert-Butyl (2R,4R)-3-[2-(1- imidazolylcarboxamido)acetyl]-2-(2-fluorophenyl)-4-thiazolidinecarboxylate may be prepared as follows: at 10 a temperature in the vicinity of 25°C, a solution of N,N'-carbonyldiimidazole (4.8 g) in anhydrous tetrahydrofuran (50 cc) is added slowly to a solution of tert-butyl (2R,4R)-3-(2-aminoacetyl)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (7 g) in 15 anhydrous tetrahydrofuran (100 cc). The reaction medium is stirred for 12 hours at this temperature, and is then concentrated to dryness under reduced pressure at 40°C. The residue obtained is dissolved in ethyl acetate (200 cc) and washed with water (2 x 50 cc). The 20 organic phase is dried over magnesium sulphate and evaporated to dryness under reduced pressure at 40°C. tert-Butyl (2R,4R)-3-[2-(1-imidazolylcarboxamido)-acetyl]-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (8.7 g) is thus obtained in the form of an oil used as 25 it is in subsequent syntheses. 182 tert-Butyl (2R,4R)-3-(2-aminoacetyl)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 34 §A, but starting from tert-butyl (2R,4R)-3-(2-tert-butoxycarbonylaminoacetyl)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (15.0 g) and iodotrimethylsilane (5.34 cc). tert-Butyl (2R,4R)-3-(2-aminoacetyl)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (10 g) is thus obtained in the form of an oil used as it is in subsequent syntheses. tert-Butyl (2R,4R)-3-(2-tert- butoxycarbonylaminoacetyl)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 34 §B, but starting from tert-butyl (2RS,4R)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (25.0 g), 2-tert-butoxycarbonylaminoacetic acid (15.5 g) and N,N'-dicyclohexylcarbodiimide (18.2 g). The crude product is purified by chromatography on silica (eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure. tert-Butyl (2R,4R)-3-(2-tert-butoxycarbonylaminoacetyl)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (25.0 g) is thus obtained in the form of an oil used as it is in subsequent syntheses. 183 Methyl (RS)-3-aminomandelate may be prepared as follows: palladinised charcoal (0.5 g/5 %) is added to solution of methyl (RS)-3-nitromandelate (15 g) in ethanol (150 cc). The suspension is stirred for 2 hours at a temperature in the vicinity of 25°C under a hydrogen atmosphere (100 kPa). The catalyst is then separated by filtration and the filtrate is concentrated tp dSffjftffess under reduced pressure at 40°C. Methyl (RS)-3-am'i1i6mandelate (13.1 g) is thus obtained in the form of an oil used as it is in subsequent syntheses.

Methyl (RS)-3-nitromandelate may be prepared according to the method described by L.S.FOSDICK and -V J.C.OALANDRA, J. Am. Chem. soc., 63, 1101 (1941). Example 80 The operation is carried out in a fashion similar to ) that descJibed in Example 38, but starting from tert- butyl (2R,4R)-3-[2-(1-imidazolylcarboxamido)acetyl]-2-* (2-fluorophenyl)-4-thiazolidinecarboxylate (2.17 g) and 2-(3-aminophenyl)ethanol (1.37 g). The crude product is purified by two successive chromatographic operations on |S.lica [eluent: methylene chloride/methanol (95/5 by volume) for the first chromatographic*operation; eluent: ethyl acetate for the second chromatographic operation). The fractions containing the expected 184 product are combined and concentrated to dryness under reduced pressure. tert-Butyl (2R,4R)-3-{2-^3-[3-(2-hydroxyethyl)phenyl]ureido}acetyl}-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (0.5 g) is thus obtained in 5 the form of an amorphous product, ([a]" = +69.0° ±2.0° (C = 0.48%; CHC13), [proton NMR (200 MHz, DMSO D6 plus several drogj^. of^ CD3C00D, 6 in ppm, J in Hz), 2 rotamers, at room temjperaturje, peak coalescence at 110°C, * characteristic chemical shifts at 110°C: 1.55 (s, 10 9H,-C(CH3)3); 2.72 (t, J = 7, 2H, ArCH2-) ; 3.31 and 3.52 (2dd, J = 12 and 6, 2H, S-CH2); 3.67 (t, J = 7, 2H, -CH20-) ; 3.8 (bd, 1H, of N-COCH2-N) ; 4.1 (d, J = 17, 1H, the other H of H-C0ChT2-N); 5.01 (t, J = 6, 1H, N-CH-COO); 6.2 (broid, 1H, -NHC0-); 6.54 (s, 1H, S-CH-N); 15 6.81 (bd, J = 7.5, 1H, in position 4 on CO-NH-Ph); 7.05 Jo 7.45 (m, 6H, aromatic); 7.93 (bt, J = 8.5, 1H, in position 6 on S-CH-Ph); 8.36 (broad, 1H, ArNHCO-)], [infrared spectrum (KBr), characteristic bands in cm"1: 3380, 2975, 2930, 2875, 1740, 1655, 1610, 1590, 1560, , 20 1490, 1460, ,'1370 * 12*30, 1150, 1050, 760, 700]. 2-(3-Aminophenyl)ethanol may be prepared according to the method described by b. CARNMALM et al., Acta Pharm. Suecica, 11, 33 (1974). 185 Example 81 The operation is carried out in a fashion similar to that described in Example 41, but starting from 2-trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-5 butoxycarbonyl-2-(2-chloro-6-fluorophenyl)-3- thiazolidinyl]-2-oxoethyl>ureido}benzoate (1.37 g) and a 1M solution of tetrabutylammonium fluoride (4.3 cc). The crude product is dissolved in a 0.5 N aqueous sodium hydroxide solution (10 cc) and washed with ethyl 10 acetate (2 x 20 cc). The aqueous phase is brought to a pH of 2 by addition of a IN aqueous sulphuric acid solution. The product precipitated is separated by filtration, washed with distilled water (2 x 5 cc) and dried in air. (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-15 (2-chloro-6-fluorophenyl)-3-thiazolidinyl]-2- oxoethyl}ureido}benzoic acid (0.12 g), m.p. 148°C, is thus obtained ([a ]g° = +3.1° ±0.8" (C = 0.518%; DMF), [proton NMR (250 MHz, DMSO D6 d in ppm, J in Hz), 2 rotamers at room temperature, peak coalescence at 20 120°C, characteristic chemical shifts at 120°C: 1.5 (s, 9H,-C(CH3)3); 3.48 (dd, J = 12.5 and 6.5. 1H, of S-CH2); 3.62 (dd, J= 12.5 and 5, 1H, the other H of S-CH2-); 3.96 (dd, J = 17.5 and 5, 1H, of N-C0CH2-N); 4.18 (ddf J = 17.5 and 5.5, 1H, the other H of N-C0CH2-25 N); 5.11 (dd, J = 6.5 and 5, N-CH-COO); 6.24 (broad, 1H, -NHC0-); 6.01 (s, 1H, S-CH-N); 7.05 to 7.65 (m, 6H, 186 aromatic); 7.98 (bs, 1H, in position 2 on CO-NH-Ph-); 8.66 (broad, 1H, ArNHCO-)], [infrared spectrum (KBr), characteristic bands in cm"1: 3380, 2980, 2930, 2700 to 2250 (broad band), 1715, 1695, 1655, 1605, 1590, 1560, 1490, 1460, 1370, 1150, 785, 760, 680]. 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl- 2 -(2-chloro-6-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}benzoate may be prepared in a fashion similar to that described in Example 34, but starting from tert-butyl (2R,4R)-3-(2-aminoacetyl)-2-(2-chloro-6-fluorophenyl)-4-thiazolidinecarboxylate (1.40 g) and 2-trimethylsilylethyl 3-isocyanatobenzoate (1.4 g). The crude product obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. 2-Trimethylsilylethyl (2R,4R)-3-{3- {2-[4-tert-butoxycarbonyl-2-(2-chloro-6-fluorophenyl)- 3-thiazolidinyl]-2-oxoethyl>ureido}benzoate (1.44 g) is thus obtained in the form of a meringue-like product used as it is in subsequent syntheses. tert-Butyl (2R,4R)-3-(2-aminoacetyl)-2-(2-chloro-6-fluorophenyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 34 187 §A, but starting from tert-butyl ( 2R,4R)-3-(2-tert-butoxycarbonylaminoacetyl)-2-(2-chloro-6-fluorophenyl)-4-thiazolidinecarboxylate (1.86 g) and iodotrimethylsilane (0.67 cc). tert-Butyl (2R,4R)-3-(2-aminoacetyl)-2-(2-chloro-6-fluorophenyl)-4-thiazolidinecarboxylate (1.4 g) is thus obtained in the form of a paste used as it is in subsequent syntheses. tert-Butyl (2R,4R)-3-(2-tert-butoxycarbonyl-aminoacetyl)-2-(2-chloro-6-fluorophenyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 34 §B, but starting from tert-butyl (2RS,4R)-2-(2-chloro-6-fluorophenyl)-4-thiazolidinecarboxylate (2.2 g), 2-tert-butoxycarbonylaminoacetic acid (1.22 g) and N,N'-dicyclohexylcarbodiimide (1.45 g). The crude product is purified by chromatography on silica (eluent: methylene chloride/methanol (98/2 by volume)] . The fractions containing the expected product are combined and concentrated to dryness under reduced pressure. tert-Butyl (2R, 4R)-3-(2-tert-butoxycarbonylaminoacetyl)-2-(2-chloro-6-fluorophenyl)-4-thiazolidinecarboxylate (1.56 g) is thus obtained in the form of a solid used as it is in subsequent syntheses. tert-Butyl (2RS,4R)-2-(2-chloro-6-fluorophenyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 34 SC, but r * i * 1^0 i 188 starting from (2RS,4R)-2-(2-chloro-6-fluorophenyl)-4-thiazolidinecarboxylic acid (6.1 g) in solution in chloroform (60 cc), concentrated sulphuric acid (1.4 cc) and an excess of isobutene. The crude product 5 obtained is purified by chromatography on silica (eluent: ethyl acetate/cyclohexane (25/75 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. tert-Butyl (2RS,4R) 2-(2-chloro-6-10 fluorophenyl)-4-thiazolidinecarboxylate (4.4 g) is thus obtained in the form of an oil used as it is in . subsequent syntheses. (2RS,4R)-2-(2-Chloro-6-fluorophenyl)-4-thiazolidinecarboxylic acid may be prepared as in 15 Example 34 §D, but starting from L-cysteine (11.4 g) and 2-chloro-6-fluorobenzaldehyde (16.7 g). (2RS,4R)-2-(2-Chloro-6-fluorophenyl)-4-thiazolidinecarboxylic acid (12.3 g), m.p. 148°C, used as it is in subsequent syntheses, is thus obtained. 2-Trimethylsilylethyl 3-isocyanatobenzoate may be prepared as in Example 21, but starting from 2-trimethylsilylethyl 3-aminobenzoate (2.37 g), trichloromethyl chloroformate (1.32 cc) and charcoal (0.21 g). 2-Trimethylsilylethyl 3-isocyanatobenzoate 25 (2.6 g) is thus obtained in the form of an oil used as it is in subsequent syntheses. 189 Example 82 The operation is carried out in a fashion similar to that described in Example 77, but starting from methyl 3-{3-{(2S)-l-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-5 fluorophenyl)-3-thiazolidinyl]-l-oxo-2-propyl>ureido}-phenylacetate (0.38 g) in a water/methanol (30/70 by volume) mixture (6 cc) and potassium hydroxide (0.05 g). The crude product is dissolved in 0.1N aqueous sodium hydroxide solution (3.5 cc). The 10 solution thus obtained is washed with ethyl acetate (2 x 10 cc), filtered and brought to a pH of 2 by addition of a IN aqueous sulphuric acid solution. The product precipitated is separated by filtration, washed with water (2x5 cc) and dried in air. 3-{3-{(2S)-1-15 [(2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3- thiazolidinyl]-l-oxo-2-propyl}ureido}phenylacetic acid (0.13 g), m.p. 110°C, is thus obtained ([c*]d° = +103° ±4° (C = 0.244%; DMF), [proton NMR (200 MHz, DMSO D6/ S in ppm, J in Hz), 2 rotamers at room temperature, peak 20 coalescence at 120°C, characteristic chemical shifts at 120°C: 1.05 (d, J = 7, 3H, -CH3): 1.55 (s, 9H,-C(CH3)3); 3.25 (dd, J = 12.5 and 7, 1H, of S-CH2); 3.52 (dd, J = 12.5 and 6, 1H, the other H of S-CH2-); 3.53 (s, 2H, ArCH2COO); 4.4 (m, 1H, N-COCH-N); 4.86 (dd, J = 7 25 and 6, N-CH-COO); 6.3 (d, J = 8, 1H, -NHCO-); 6.83 (s,lH, S-CH-N); 6.89 (bd, J = 8, 1H, in position 4 on 190 CO-NH-Ph-); 7.10 to 7.5 (m, 6H, aromatic); 8.0 (bt, J = 8.5/ 1H, in position 6 on S-CH-Ph-); 8.29 (broad, 1H, ArNHCO-)], [infrared spectrum (KBr), characteristic bands in cm"1: 3380, 2980, 2935, 2700 to 2250 (broad 5 band), 1735, 1640, 1615, 1595, 1560, 1490, 1460, 1370, 1235, 1155, 760, 705].

Methyl 3-{3-{(2S)-l-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-l-oxo-2-propyl>ureido}phenylacetate may be prepared in a 10 fashion similar to that described in Example 34, but starting from tert-butyl (2R,4R)-3-((2S)-2-aminopropionyl)-2-(2-fluorophenyl)-4-thiazolidine-carboxylate (0.85 g) and methyl 3-isocyanatophenyl-acetate (0.53 g). The crude product obtained is 15 purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. Methyl 3-{3-{(2S)-l-[(2R,4R)-4-tert-butoxycarbonyl-2-20 (2-fluorophenyl)-3-thiazolidinyl]-l-oxo-2- propyl}ureido}phenylacetate (0.38 g) is thus obtained in the form of an oil used as it is in subsequent syntheses. tert-Butyl (2R,4R)-3-((2S)-2-aminopropionyl)-2-(2-25 fluorophenyl)-4-thiazolidinecarboxylate may be prepared / 191 in a fashion similar to that described in Example 34 §A, but starting from tert-butyl (2R,4R)-3-((2S)-2-tert-butoxycarbonylaminopropionyl) -2- ( 2-f luorophenyl) -4-thiazolidinecarboxylate (1.0 g) and iodotrimethylsilane (0.39 cc). tert-Butyl (2R,4R)-3-((2S)-2-aminopropionyl) -2-(2-fluorophenyl)-4-thiazolidinecarboxylate (0.85 g) is thus obtained in the form of an oil, used as it is in subsequent syntheses. tert-Butyl (2R,4R)-3-((2S)-2-tert-butoxycarbonylaminopropionyl)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 34 §B, but starting from tert-butyl (2RS,4R)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (2.0 g), N-tert-butoxycarbonyl-L-alanine (1.36 g) and N,N'-dicyclohexylcarbodiimide (1.47 g) . The crude product is purified by chromatography on silica (eluent: ethyl acetate/cyclohexane (15/85 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure. tert-Butyl (2R,4R)-3-((2S)-2-tert-butoxycarbonyl-aminopropionyl)-2-(2-fluorophenyl)-4- thiazolidinecarboxylate (1.0 g) is thus obtained in the form of an oil, used as it is in subsequent syntheses. 192 Example 83 The operation is carried out in a fashion similar to that described in Example 77, but starting from methyl 3-{3-{(2R)-l-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-5 fluorophenyl)-3-thiazolidinyl]-1-oxo-2-propyl>ureido}-phenylacetate (0.48 g) in a water/methanol (30/70 by volume) mixture (7 cc) and potassium hydroxide (0.06 g). The product obtained after filtration on silica (eluent: ethyl acetate/methanol (90/10 by volume)] is 10 dissolved in 0.1N aqueous sodium hydroxide solution (7.0 cc). The solution thus obtained is filtered and brought to a pH of 2 by addition of IN aqueous sulphuric acid solution. The product precipitated is separated by filtration, washed with water (2 x 5 cc) 15 and dried in air. 3-{(2R)-3-{l-[(2R1,4R)-4-tert- butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-1-oxo-2-propyl}ureido}phenylacetic acid (0.25 g), m.p. 200°C, is thus obtained ([a]" = +83° ± 2.0° (C = 0.48%; DMF), [proton NMR (250 MHz, DMSO D6, d in ppm, J in Hz), 20 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 120°C: 127 (d, J = 7.5, 3H, -CH3) ; 1.54 (s, 9H,-C(CH3)3); 3.40 and 3.56 (2dd, J = 12.5 and 6.5, 2H, S-CH2-); 3.50 (s, 2H, -CH2COO-); 4.50 (m, 1H, N-COCH-N); 5.45 (broad, 1H, 25 N-CH-COO); 6.3 (d, J « 8.5, 1H, -NHCO-); 6.50 (s, 1H, S-CH-N); 6.9 (bd, J = 8, 1H, in position 4 of 193 CO-NH-Ph); 7.0 to 7.45 (m, 6H, aromatic); 7.9 (bt, J = 8.5, 1H, in position 6 on S-CH-Ph-); 8.3 (broad, 1H, ArNHCO-)], [infrared spectrum (KBr), characteristic bands in cm"1: 3380, 2975, 2930, 2700 to 2250 (broad band), 1730, 1640, 1610, 1595, 1555, 1490, 1455, 1365, 1230, 1150, 755, 700].

Methyl 3-{3-{(2R)-l-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-l-oxo-2-propyl>ureido}phenylacetate may be prepared in a fashion similar to that described in Example 34, but starting from tert-butyl (2R,4R)-3-((2R)-2-aminopropionyl)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (0.55 g) and methyl 3-isocyanatophenylacetate (0.37 g). The crude product obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (40/60 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. Methyl 3-{3-{ (2R)-1-[ (2R, 4R) ^-tert-butoxycarbonyl^-(2-f luorophenyl)-3-thiazolidinyl ] -1-oxo-2-propyl>ureido}phenylacetate (0.48 g) is thus obtained in the form of an amorphous product used as it is in subsequent syntheses. tert-Butyl (2R,4R)-3-((2R)-2-aminopropionyl)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate may be prepared ? / 194 in a fashion similar to that described in Example 34 §A, but starting from tert-butyl (2R,4R)-3-((2R)-2-tert-butoxycarbonylaminopropionyl)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (0.8 g) and iodotrimethylsilane (0.30 cc) . tert-Butyl (2R,4R)-3-((2R)-2-aminopropionyl)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (0.55 g) is thus obtained in the form of an oil used as it is in subsequent syntheses. tert-Butyl (2R,4R)-3-((2R)-2-tert- butoxycarbonylaminopropionyl)-2-(2-fluorophenyl)]-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 34 §B, but starting from tert-butyl (2RS,4R)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (2.0 g), N-tert-butoxycarbonyl-D-alanine (1.36 g) and N,N'-dicyclohexylcarbodiimide (1.47 g). The crude product is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (15/85 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure. tert-Butyl (2R,4R)-3-((2R)-2-tert- butoxycarbonylaminopropionyl)-2-(2-fluorophenyl)]-4-thiazolidinecarboxylate (1.0 g) is thus obtained in the form of an oil, used as it is in subsequent syntheses. 24 3^1^ 195 Example 84 Palladinised charcoal (0.1 g/10 %) is added to a solution of benzyl 2-{3-{3-(2-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-5 oxoethyl>ureido}phenyl}propionate (B form) (0.35 g) in ethyl acetate (40 cc). The suspension is stirred for 48 hours at a temperature in the vicinity of 25°C under a hydrogen atmosphere (100 kPa). The catalyst is then separated by filtration and the filtrate is 10 concentrated to dryness under reduced pressure at 40°C. The residue obtained is dissolved in 0.1N aqueous sodium hydroxide solution (10 cc) and washed with ethyl ether (2 x 10 cc). The aqueous phase is brought to a pH of 2 by addition of a IN aqueous sulphuric acid 15 solution. The product precipitated is separated by filtration, is washed with water (2 x 10 cc) and dried in air. 2-{3-{3-{2-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl}ureido>-phenyl}propionic acid (B form) (0.12 g), m.p. 126°C, is 20 thus obtained. [a]d° = +97 + 2° (C = 0.502%; DMF) Proton NMR (200 MHz, DMSO D6 plus several drops of CD3COOD, S in ppm, J in Hz), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic 25 chemical shifts at 120°C: 1.4 (d, J = 7.5, 3H, -CH3); 1.54 (s, 9H,-C(CH3)3); 3.32 (2dd, J = 12.5 and 6.5, 1H, 196 24 3 3 of S-CH2); 3.52 (dd, J = 12 and 7, 1H, the other H of S-CH2-) ; 3.62 (q, J = 7.5, 1H, Ar-CH-COO); 3.78 (bd, 1H, of N-COCH2-N); 4.07 (d, J = 17, 1H, the other H of N-C0CH2-N); 5.0 (dd, J = 7 and 6.5, 1H, N-CH-COO); 6.17 5 (broad, 1H , -NHCO-); 6.53 (s, 1H, S-CH-N); 6.86 (bd, J = 8, 1H, in position 4 on CO-NH-Ph-); 7.10 to 7.5 (m, 6H, aromatic); 7.92 (bt, J = 8.5, 1H, in position 6 on S-CH-Ph-); 8.43 (broad, 1H, ArNHCO-).

Infrared spectrum (KBr), characteristic bands in cm"1: 10 3380, 2975, 2930, 2650 to 2250 (broad band), 1735, 1650, 1610, 1595, 1560, 1490, 1455, 1370, 1230, 1150, 760, 700.

A. Benzyl 2-{3-{3-{2-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-15 oxoethyl}ureido}phenyl}propionate (B form) may be prepared in a fashion similar to that described in Example 34, but starting from tert-butyl (2R,4R)-3-(2-aminoacetyl)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (1.02 g) and benzyl 2—(3— 20 isocyanatophenyl)propionate (B form) (0.89 g). The crude product is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (50/50 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced 25 pressure at 40°C. Benzyl 2-{3-{3-(2-[(2R,4R)-4-tert- 2 4 3 li 1 4 197 butoxycarbonyl-2-( 2-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}phenyl}propionate (B form) (1.2 g) is thus obtained in the form of a yellow paste, used as it is in subsequent syntheses.

B. Benzyl 2-(3-isocyanatophenyl)propionate (B form) may be prepared as in Example 21, but starting from (+)-[benzyl 2-(3-aminophenyl)propionate] (2.85 g), trichloromethyl chloroformate (1.48 cc) and charcoal (0.24 g). Benzyl 2-(3-isocyanatophenyl)propionate (B 10 form) (3.1 g) is thus obtained in the form of an orange-oil used as it is in subsequent syntheses.

C. (+)-[Benzyl 2-(3-aminophenyl)propionate] may be prepared as follows: ammonium chloride (75 g) and zinc powder (37.0 g) are added to a mixture of (+)-[benzyl 15 2-(3-nitrophenyl)propionate] (8.0 g) in methanol (35 cc) and water (300 cc). The reaction medium is heated under reflux for 1 hour, then cooled to 0°C. The insoluble salts are separated by filtration and the filtrate is extracted with ethyl ether (3 x 200 cc). 20 The collected organic phases are washed successively with water (100 cc) and with a saturated aqueous solution of sodium chloride (100 cc). After drying over magnesium sulphate concentrating to dryness under reduced pressure at 40°C, (+)-[benzyl 2-(3-25 aminophenyl)propionate] (6.7 g) is thus obtained in the 24 •• 198 form of a yellow oil, used as it is in subsequent syntheses.

D. (+)-[Benzyl 2-(3-nitrophenyl)propionate] may be prepared as follows: oxalyl dichloride (4.72 cc) is 5 slowly added to a mixture containing (+)-[2-(3-nitrophenyl)propionic acid] (9.75 g) and dimethylformamide (0.5 cc) in 1,2-dichloroethane (100 cc). The reaction medium is stirred for 3 hours at a temperature in the vicinity of 25°C, followed by the 10 addition of benzyl alcohol (5.4 g). Stirring is continued for 12 hours at the same temperature, then the reaction mixture is washed successively with a saturated aqueous solution of sodium bicarbonate (2 x 200 cc), with water (100 cc) and with a saturated 15 aqueous solution of sodium chloride (100 cc). The collected organic phases are washed successively with water (100 cc) and with a saturated aqueous solution of sodium chloride (100 cc). The collected organic phases are dried over magnesium sulphate and concentrated to 20 dryness under reduced pressure at 40°C. The residue obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced 25 pressure at 40°C. (+)-[Benzyl 2-(3- nitrophenyl)propionate] (11.5 g) is thus obtained in the form of a yellow oil, used as it is in subsequent 2'i ; 199 syntheses.

E. (+)-[2-(3-Nitrophenyl)propionic acid] may be prepared as follows: 2-(3-nitrophenyl)-N-[(R)-2-hydroxy-l-phenylethylJpropionamide (B form) (21.5 g) in 5 solution in a mixture of dioxane (450 cc) and 4N aqueous hydrochloric acid solution (450 cc) is heated to a temperature in the vicinity of 80°C for 5 hours, then stirred for 12 hours at a temperature in the vicinity of 25°C. The reaction mixture is concentrated 10 to half by evaporation under reduced pressure at 40 °C, diluted by addition of water (500 cc) and extracted with diethyl ether (2 x 500 cc). The collected organic phases are washed successively with water (3 x 250 cc) and with a saturated aqueous solution of sodium 15 chloride (250 cc). After drying over magnesium sulphate and concentrating to dryness under reduced pressure at 40°C, (+)-[2-(3-nitrophenyl)propionic acid] (14 g) is thus obtained in the form of a cream-coloured solid used as it is in subsequent syntheses.

F. 2-(3-Nitrophenyl)-N-[(R)-2-hydroxy-l- phenylethyl]propionamide (B form) may be prepared as follows: oxalyl dichloride (17.2 cc) is added slowly to a mixture containing (RS)-2-(3-nitrophenyl)propionic acid (39.0 g) and dimethylformamide (0.5 cc) in 1,2-25 dichloroethane (400 cc). The reaction medium is stirred for 3 hours at a temperature in the vicinity of 259C, "•? 200 then concentrated to dryness under reduced pressure at 40°C. The residue obtained is dissolved in 1,2-dichloroethane (150 cc). The acid chloride solution thus obtained is added to a solution of (2R)-2-5 phenylglycinol (27.4 g) while maintaining the temperature of the reaction medium below 10°C. At the end of the addition, the mixture is stirred for 12 hours at a temperature in the vicinity of 25°C, then washed successively with water (1 x 1000 cc), with IN 10 aqueous hydrochloric acid solution (500 cc), with water (2 x 100 cc) and with a saturated aqueous solution of sodium chloride (1 x 500 cc). The organic phase collected is dried over magnesium sulphate and concentrated to dryness under reduced pressure at 40°C. 15 The two diastereoisomers obtained are separated by chromatography on silica [eluent: methylene chloride/ethyl acetate (70/30 by volume)]. The fractions containing each of the two diastereoisomers are combined and concentrated to dryness under reduced 20 pressure at 40°C. 2-(3-Nitrophenyl)-N-[(R)-2-hydroxy-l-phenylethyl]propionamide (A form) (21.0 g) (first elution product), m.p. 135°C, and 2-(3-nitrophenyl)-N-[(R)-2-hydroxy-1-phenylethyljpropionamide (B form) (19.0 g) (second elution product), m.p. 150cC, are thus 25 obtained. 201 Example 85 The operation is carried out in a fashion similar to that described in Example 84, but starting from benzyl 2-{3-{3-{2-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-5 fluorophenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}-phenyl propionate (A form) (3.8 g) and palladinised charcoal (0.8 g/10 %). 2-{3-{3-(2-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}phenyl}propionic acid (A form) (1.4 g), 10 m.p. 145°C, is thus obtained. [o]2° = +20.0 + 1.1° (C = 0.539%; DMF) .

Proton NMR (200 MHz, DMSO D6, 5 in ppm, J in Hz), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic chemical shifts at 120"C: 1.4 (d, 15 J = 7, 3H, -CH3); 1.53 (s, 9H, -C(CH3)3); 3.3 and 3.48 (2dd, J = 12.5 and 6, 2H, S-CH2) ; 3.6 (q, J= 7, 1H, Ar-CH-COO); 3.77 and 4.05 (2dd, J = 17.5 and 5.5, 2H, N-C0CH2-N); 5.0 (t, J = 6, 1H, N-CH-COO); 6.17 (t, J = 5.5, 1H, -NHC0-); 6.53 (s, 1H, S-CH-N); 6.85 (bd, 20 J = 7.5, 1H, in position 4 on CO-NH-Ph); 7.05 to 7.45 (m, 6H, aromatic); 7.91 (dt, J = 8 and 1, 1H, in position 6 on S-CH-Ph); 8.43 (broad, 1H, ArNHCO-).

Infrared spectrum (KBr), characteristic bands in cm'1: 3380, 3100 to 3000, 2975, 2930, 2875, 2750 to 2350 202 (wide band), 1735, 1650, 1615, 1595, 1555, 1490, 1460, 1420, 1395, 1370, 1155, 760, 700.

Benzyl 2-{3-{3-{2-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}phenyl}propionate (A form) may be prepared in a fashion similar to that described in Example 34, but starting from tert-butyl (2R,4R)-3-(2-aminoacetyl)-2-(2-fluorophenyl)-4-thiazolidinecarboxylate (4.0 g) and benzyl 2-(3-isocyanatophenyl)-propionate (4.0 g). The crude product is purified by chromatography on silica [eluent: ethyl acetate/ cyclohexane (40/60 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40"C. Benzyl 2-{3-{3-{2-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}-phenyl}propionate (3.8 g) is thus obtained in the form of an amorphous product, used as it is in subsequent syntheses.

Benzyl 2-(3-isocyanatophenyl)propionate (A form) may be prepared as in Example 21, but starting from (-)-[benzyl 2-(3-aminophenyl)propionate] (4.0 g), trichloromethyl chloroformate (2.1 cc) and charcoal (0.33 g). Benzyl 2-(3-isocyanatophenyl)propionate (4.7 g) is thus obtained in the form of an orange oil, used as it is in 203 subsequent syntheses.

(-)-[Benzyl 2-(3-aininophenyl)propionate] maybe prepared in a fashion similar to that described in Example 84C, but starting from (-)-[benzyl 2—(3 — nitrophenyl)propionate] (5.3 g), ammonium chloride (50 g) and zinc powder (24.8 g). (-)-[Benzyl 2-(3-aminophenyl)propionate] (4.2 g) is thus obtained in the form of a yellow oil, used as it is in subsequent syntheses.

(-)-[Benzyl 2-(3-nitrophenyl)propionate] may be prepared in a fashion similar to that described in Example 84D, but starting from (—)—[2-(3— nitrophenyl)propionic acid] (4.45 g), dimethylformamide (0.3 cc) and oxalyl dichloride (2.15 cc). The crude product is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. (-)-[Benzyl 2-(3- nitrophenyl)propionate] (5.6 g) is thus obtained in the form of a yellow oil, used as it is in subsequent syntheses. (-)-[2-(3-Nitrophenyl)propionic acid] may be prepared in a fashion similar to that described in Example 84E, but starting from 2-(3-nitrophenyl)-N-[(R)-2-hydroxy-1- 204 phenylethyljpropionamide (A form) (9.4 g) in solution in a mixture of dioxane (200 cc) and 4N aqueous hydrochloric acid solution (200 cc). (—)—[2—(3— Nitrophenyl)propionic acid] (5.85 g) is thus obtained 5 in the form of a cream-coloured solid used as it is in subsequent syntheses.

Example 86 The operation is carried out in a fashion similar to that described in Example 77, but starting from methyl 10 (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2- (2,3-difluorophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}phenylacetate (0.68 g) in a water/methanol (30/70 by volume) mixture (6 cc) and potassium hydroxide (0.08 g). The crude product 15 (0.45 g) is dissolved in 0.1N aqueous sodium hydroxide solution (7.5 cc). The solution thus obtained is washed with diethyl ether, (2 x 10 cc), brought to a pH of 2 by addition of a IN aqueous sulphuric acid solution, then extracted with ethyl acetate (2 x 20 cc). The 20 organic phases are combined, dried over magnesium sulphate and concentrated to dryness under reduced pressure at 40°C. The product obtained is purified by chromatography on silica [eluent: methylene chloride/methanol (80/20 by volume)]. The fractions 25 containing the expected product are combined and 205 concentrated to dryness under reduced pressure at 40°C. (2R,4R)-3-{3-{2-[4-tert-Butoxycarbonyl-2-(2,3-difluorophenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}phenylacetic acid (0.05 g) is thus 5 obtained in the form of an amorphous product. [a]" = +64 ±2° (C = 0.557%, CHC13) proton NMR (200 MHz, DMSO Ds, plus several drops of CDjCOOD, 6 in ppm, J in Hz), 2 rotamers at room temperature, peak coalescence at 120°C, characteristic 10 chemical shifts at 120°C: 1.52 (s, 9H,-C(CH3)3); 3.31 and 3.51 (2dd, J = 12.5 and 6, 2H, S-CH2) ; 3.46 (s, 2H, Ar-CH2-COO); 3.82 (bd, 1H, of N-C0CH2-N) ; 4.05 (d, J = 17, 1H, the other H of N-C0CH2-N); 5.0 (t, J = 6, 1H, N-CH-COOO); 6.15 (broad, 1H, -NHC0-); 6.5 (s, 1H, 15 S-CH-N); 6.82 (bd, J = 7.5, 1H, in position 4 on CO-NH-Ph); 7.05 to 7.45 (m, 5H, aromatic); 7.68 (bt, J = 8 and 1, 1H, in position 6 on S-CH-Ph); 8.7 (broad, 1H, ArNHCO-).

Infrared spectrum (KBr), characteristic bands in cm"1: 20 3380, 3100 to 3000, 2975, 2930, 2750 to 2350 (wide band), 1735, 1655, 1615, 1595, 1560, 1490, 1405, 1370, 1150, 775, 745. 206 Methyl (2R,4R)—3 — {3 — <2 — [4-tert-butoxycarbonyl-2-(2,3-difluorophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}phenylacetate may be prepared in a fashion similar to that described in Example 41 A, but starting from tert-butyl (2RS,4R)-2-(2,3-difluorophenyl)-4-thiazolidinecarboxylate (1.5 g), 2-{3-[3-methoxycarbonylmethylphenyl]ureido}acetic acid (1.33 g) and N,N'-dicyclohexylcarbodiimide (1.0 g). The crude product is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (40/60 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. Methyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(2,3-difluorophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}phenylacetate (0.4 g) is thus obtained in the form of a colourless oil, used as it is in subsequent syntheses. tert-Butyl (2RS,4R)-2-(2,3-difluorophenyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 34 C, but starting from (2RS,4R)-2-(2,3-difluorophenyl)-4-thiazolidinecarboxylic acid (14.3 g) in solution in chloroform (50 cc), concentrated sulphuric acid (3.5 cc) and an excess of isobutene. The crude product obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (10/90 by volume)]. 207 The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. tert-Butyl (2RS,4R)-2-(2,3-difluorophenyl)-4-thiazolidinecarboxylate (14.0 g) is 5 thus obtained in the form of a thick yellow oil, a mixture of the (2R,4R) and (2S,4R) and isomers, used as it is in subsequent syntheses. (2RS,4R)-2-(2,3-difluorophenyl)-4-thiazolidine-carboxylic acid may be prepared as in Example 34 D, but 10 starting from L-cysteine (8.5 g) and 2,3-difluoro- benzaldehyde (10.1 g). (2RS,4R)-2-(2,3-difluorophenyl)-4-thiazolidinecarboxylic acid (3.7 g), m.p. 120°C, used as it is in subsequent syntheses, is thus obtained.

Example 87 By proceeding in a fashion similar to that described in Example 41 SA, but starting from (2RS,4R)-2,4-diphenylthiazolidine (1.2 g), 2—[3—(3— methylphenyl)ureido]acetic acid (1.04 g) and N,N'-dicyclohexylcarbodiimide (1.03 g) in acetonitrile 20 (15 cc), and after treatment, (2RS,4R)-l-{2-[3-(3-methylphenyl)ureido]acetyl}-2,4-diphenylthiazolidine (0.98 g) is obtained in the form of a meringue-like product. 208 Mass (chemical ionisation with ammonia 70eV, m/z), 432 (Mt).

Infrared spectrum (KBr) characteristic bands in cm"1 3340, 3085, 3060, 3030, 2920, 1635, 1610, 1490, 1450, 5 1560, 780, 765, 695. (2RS,4R)-2,4-diphenylthiazolidine may be prepared as in Example 34 SD, but starting from (R)-2-amino-2-phenyl-ethanethiol hydrochloride (1.9 g), triethylamine (2.75 cc) and benzaldehyde (1.15 cc) in ethanol (25 10 cc). (2RS,4R)-2,4-diphenylthiazolidine (1.15 g), m.p. 120°C, is thus obtained.

(R)-2-amino-2-phenylethanethiol may be prepared according to the method described in the patent application JP 57193447 (C.A. 98, 178924r).

Example 88 By proceeding in a fashion similar to that described in Example 9, but starting from methyl (2RS,4R)-3-{3-{2-(2-fluorophenyl)-4-phenyl-3-thiazolidinyl]-2-oxoethyl>ureido}phenylacetate (1.35 g) in solution in 20 methanol (25 cc) and potassium hydroxide (0.22 g) dissolved in water (5 cc), and after treatment, (2RS,4R)-3-{3-{2-(2-fluorophenyl)-4-phenyl-3- 209 thiazolidinyl]-2-oxoethyl>ureido}phenylacetic acid (0.45 g) is obtained in the form of a meringue-like product.

Mass (chemical ionisation with ammonia, 70eV, m/z), 494 5 (MT), 343.

Infrared spectrum (KBr), characteristic bands in cm"1 3375, 3060, 3025, 2930, 2700 to 2250, 1710, 1640, 1610, 1485, 1455, 1560, 760, 700.

Methyl (2RS,4R)-3-{3-(2-(2-fluorophenyl)-4-phenyl-3-10 thiazolidinyl]-2-oxoethyl>ureido}phenylacetate may be prepared as described in Example 41 §A, but starting from (2RS,4R)-2-(2-fluorophenyl)-4-phenylthiazolidine (1.3 g), 2-[3-(3-methoxycarbonylmethylphenyl )ureido]acetic acid (1.33 g) and N,N'-15 dicyclohexylcarbodiimide (1.03 g) in acetonitrile (15 cc). After treatment, methyl (2RS,4R)-3-{3-{2-(2-fluorophenyl)-4-phenyl-3-thiazolidinyl]-2-oxoethyl}ureido}phenylacetate (1.5 g) is obtained in the form of an oil used as it is in subsequent 20 syntheses. (2RS,4R)-2-(2-Fluorophenyl)-4-phenylthiazolidine may be prepared as in Example 34 §D, but starting from (R)-2-amino-2-phenylethanethiol (1.9 g), triethylamine 210 (2.75 cc) and 2-fluorobenzaldehyde (1.37 g) in ethanol (25 cc). (2RS,4R)-2-(2-Fluorophenyl)-4-phenyl-thiazolidine (1.5 g) is thus obtained in the form of an oil, used as it is in subsequent syntheses.

Example 89 The operation is carried out in a fashion similar to that described in Example 9, but starting from tert-butyl (2RS,5SR)-l-{2-[3-(3-ethoxycarbonylphenyl)ureido]acetyl}-5-(2-methylphenyl)prolinate (0.9 g) in solution in methanol (30 cc) and potassium hydroxide (0.1 g) dissolved in water (15 cc). After treatment and recrystallisation in a diisopropyl ether/isopropyl acetate (9/1 by volume) mixture, (2RS,5SR)-3-{3-{2-[4-tert-butoxycarbonyl-5-(2-methylphenyl)-1-pyrrolidinyl]-2-oxoethyl}ureido}benzoic acid (0.35 g), m.p. 235°C, is obtained. tert-Butyl (2RS,5RS)-l-{2-[3-(3-ethoxycarbonyl-phenyl)ureido]acetyl}-5-(2-methylphenyl)prolinate may be prepared as described in Example 41 §A, but starting from tert-butyl (2RS,5SR)-5-(2-methylphenyl)prolinate (1.3 g), 2-[3-(3-ethoxycarbonylphenyl)ureido]acetic acid (1.32 g) and N,N'-dicyclohexylcarbodiimide (1.03 g) in tetrahydrofuran (50 cc). After treatment, tert-butyl (2RS,5RS) — 1—<2—[3—(3-ethoxycarbonylphenyl)- f- A v _ - 211 ureido]acetyl}-5-(2-methylphenyl)prolinate (1.9 g) is obtained in the form of a meringue-like product, used as it is in subsequent syntheses. tert-Butyl (2RS,5SR)-5-(2-methylphenyl)prolinate may be 5 prepared as follows: a suspension of magnesium (3 g) in a solution of a mixture (4 g) of the two 4-position epimers of tert-butyl (2RS,5RS)-5-(2-methylphenyl)-4-phenylsulphonylprolinate in methanol (2 00 cc) is stirred for three hours at a temperature in the 10 vicinity of 20°C. The reaction mixture is then poured into a normal aqueous hydrochloric acid solution (200 cc), then extracted with dichloromethane (3 x 200 cc). The organic extracts are combined, washed with a saturated aqueous sodium chloride solution 15 (2 x 100 cc), dried over magnesium sulphate and concentrated under reduced pressure. The residue is subjected to chromatography on silica [eluent: cyclohexane/ethyl acetate (70/30 by volume)]. The fractions containing the expected product are combined 20 and concentrated under reduced pressure. tert-Butyl (2RS,5SR)-5-(2-methylphenyl)prolinate (0.6 g) is thus obtained in the form of an oil, used as it is in subsequent syntheses.

A- tert-Butyl (2RS,5RS)-5~(2-methylphenyl)-4-25 phenylsulphonylprolinate may be prepared as follows: triethylamine (2.8 cc) at a temperature in the vicinity • . < 4 212 of 20°C is added dropwise to a suspension of silver acetate (5 g) in a solution of phenyl vinyl sulphone (3.4 g) and of tert-butyl N-(ortho-methylbenzylidene)-glycinate (4.7 g) in acetonitrile (150 cc). The 5 reaction mixture is stirred for two hours at a temperature in the vicinity of 20 °C, then poured into a saturated aqueous ammonium chloride solution (200 cc). The aqueous phase is filtered and extracted with dichloromethane (3 x 100 cc). The organic extracts are 10 combined, washed with a saturated aqueous sodium chloride solution (100 cc), dried over magnesium sulphate and concentrated under reduced pressure. After recrystallisation in ethyl ether, tert-butyl (2RS,5RS)-5-(2-methylphenyl)-4-phenylsulphonylprolinate (5 g) 15 (mixture of the two 4-position epimers), m.p. 180°C, is thus obtained.

B- tert-Butyl N-(ortho-methylbenzylidene)glycinate may be prepared as follows: triethylamine (2.8 cc) at a temperature in the vicinity of 20°C is added dropwise 20 to a suspension of 4A molecular sieve (3 g) in a solution of tert-butyl glycinate hydrochloride (3.35 g) in ortho-tolualdehyde (2.4 cc) and dichloromethane (50 cc). The reaction mixture is stirred for twenty hours at a temperature in the vicinity of 20°C, 25 filtered and concentrated under reduced pressure. The residue is taken up in diethyl ether (250 cc), filtered and concentrated under reduced pressure. tert-Butyl N- 213 (ortho-methylbenzylidene)glycinate (4.7 g) is thus obtained in the form of an oil, used as it is in subsequent syntheses.

Example 90 The operation is carried out in a fashion similar to that described in Example 9, but starting from tert-butyl (2RS,5SR)-l-{2-[3-(3- ethoxycarbonylphenyl)ureido]acetyl}-5-(2-fluorophenyl)-prolinate (1.1 g) in solution in methanol (30 cc) and potassium hydroxide (0.12 g) dissolved in water (15 cc). After treatment and recrystallisation in diisopropyl ether, (2RS,5SR)-3-{3-{2-[2-tert-butoxy-carbonyl-5-(2-fluorophenyl)-1-pyrrolidinyl]-2-oxoethyl}ureido}benzoic acid (0.4 g), m.p. 180°C, is obtained. tert-Butyl (2RS,5SR)-l-{2-[3-(3-ethoxycarbonylphenyl)ureido]acetyl> —5—(2— fluorophenyl)prolinate may be prepared as described in Example 41 §A, but starting from tert-butyl (2RS,5SR)-5-(2-fluorophenyl)prolinate (0.8 g), 2—[3-(3 — ethoxycarbonylphenyl)ureido]acetic acid (0.8 g) and N,N'-dicyclohexylcarbodiimide (0.62 g) in tetrahydrofuran (30 cc). After treatment, tert-butyl (2RS,5SR)-l-{2-[3-(3-ethoxycarbonylphenyl)- 214 ureido]acetyl}-5-(2-fluorophenyl)prolinate (1.5 g) is obtained in the form of a meringue-like product, used as it is in subsequent syntheses.

A - tert-Butyl (2RS,5SR)-5-(2-fluorophenyl)prolinate 5 may be prepared as follows: a suspension of disodium hydrogen phosphate (5.7 g) and of 6% sodium amalgam (in mercury) (7.7 g) in a solution of a mixture (4.06 g) of the two 4-position epimers of tert-butyl (2RS,5RS)-5-(2-fluorophenyl)-4-phenylsulphonyl-prolinate in 10 methanol (150 cc) is stirred for twenty hours at a temperature in the vicinity of 20°C. The reaction mixture is then poured into water (200 cc) and the mercury is separated by decantation. The aqueous phase is extracted with ethyl acetate (3 x 100 cc). The 15 organic extracts are combined, washed with water (2 x 100 cc), dried over magnesium sulphate and concentrated under reduced pressure. The residue is subjected to chromatography on silica [eluent: cyclohexane/ethyl acetate (70/30 by volume)]. The 20 fractions containing the expected product are combined and concentrated under reduced pressure. tert-Butyl (2RS,5SR)-5-(2-fluorophenyl)prolinate (0.4 g) is thus obtained in the form of an oil, used as it is in subsequent syntheses. tert-Butyl (2RS,5RS)-5-(2-fluorophenyl)-4-phenyl-sulphonylprolinate may be prepared as described in / > ; u 215 Example 89 §A, but starting from tert-butyl N-(ortho-fluorobenzylidene)glycinate (4.8 g), silver acetate (5 g), phenyl vinyl sulphone (3.4 g) and triethylamine (2.8 cc). After treatment and recrystallisation in 5 ethyl ether, tert-butyl (2RS,5RS)-5-(2-fluorophenyl)-4-phenylsulphonyl prolinate (8 g), mixture of the two 4-position epimers, m.p. 200°C, is obtained. tert-Butyl N-(ortho-fluorobenzylidene)glycinate may be prepared as described in Example 89 §B, but starting 10 from ortho-fluorobenzaldehyde (2 cc), tert-butyl glycinate hydrochloride (3.35 g), triethylamine (2.8 cc) and 4A molecular sieve (3 g) in dichloromethane (50 cc). After treatment, tert-butyl N-(ortho-fluorobenzylidene)glycinate (4.8 g) is obtained 15 in the form of an oil, used as it is in subsequent syntheses.

Example 91 The operation is carried out in a fashion similar to that described in Example 2, but starting from tert-20 butyl (2RS,5SR)-1-(2-aminoacetyl)-5-phenylprolinate (1.12 g) and para-chlorophenyl isocyanate (1.3 cc) in tetrahydrofuran (50 cc). After treatment, tert-butyl (2RS,5SR)-1-{2-[3-(4-chlorophenyl)ureido]acetyl>-5-phenylprolinate (1.2 g) is obtained in the form of an 25 amorphous solid [proton NMR (250 MHz, DMSO D6, 6 in 216 ppm), 1.50 (s, 9H, (CH3)3); 1.85 (m, 2H, CH2) ; 2.2 and 2.4 (2m, 2H, CH2) ; 3.25 and 3.85 (ABX, 2H, CH2N); 4.30 (dd, 1H, CHN); 5.20 (dd, 1H, CHN); 6.3 (t, 1H exchangeable, NH); 7.2 to 7.6 (m, 9H, aromatic); 9 (s, 5 1H exchangeable, NH)], [infrared spectrum (KBr), characteristic bands in cm"1 3370, 3065, 3030, 2980, 2930, 2875, 1735, 1595, 1490, 1450, 1545, 1365, 1150, 830, 760, 700].

Example 92 The operation is carried out in a fashion similar to that described in Example 3, but starting from tert-butyl (2RS,5SR)-l-(2-aminoacetyl)-5-phenylprolinate (3.05 g), N,N'-carbonyldiimidazole (1.78 g) and tetrabutylammonium (RS)-1-(3-aminophenyl)-15 ethanesulphonate (4.5 g) in 1,2-dichloroethane (100 cc). After treatment, potassium (2RS,5SR)-l-{3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}phenyl}ethanesulfonate (0.6 g) (mixture of the two 1-position epimers), is obtained in the form 20 of an amorphous solid [proton NMR (200 MHz, DMSO Ds, 6 in ppm,), 1.6 (s+d, 12H, CCH3 and (CH3)3); 1.8 to 2.4 (m, 4H, 2 CH2) ; 3.5 (m, 1H, CHS03) ; 3.1 and 3.8 (ABX, 2H, CHZN); 4.2 (dd, 1H, CHN); 5.1 (dd, 1H, CHN); 6.2 (t, 1H exchangeable, NH); 6.8 to 7.6 (m, 9H, aromatic); 25 8.7 (bs, 1H exchangeable, NH)], [infrared spectrum 217 (KBr), characteristic bands in cm"* 3380, 3060, 3025, 2975, 2930, 2875, 1730, 1555, 1490, 1445, 1390, 1360, 1215, 1115, 1030, 790, 755, 700].

Example 93 The operation is carried out in a fashion similar to that described in Example 41 §A, but starting from tert-butyl (2RS,5SR)-5-phenylprolinate (4.95 g), 2 — [3— (3-methoxycarbonylphenyl)ureido]acetic acid (5.04 g) and N,N'-dicyclohexylcarbodiimide (4.12 g) in 10 tetrahydrofuran (75 cc). After treatment and recrystallisation in a diisopropyl ether/isopropyl acetate (90/10 by volume) mixture, tert-butyl (2RS,5SR) l-{2-[3-(3-methoxycarbonyl)ureido]acetyl}-5-phenylprolinate (1.2 g), m.p. 141°C, is obtained. 2-[3-(3-Methoxycarbonylphenyl)ureido]acetic acid may be prepared as described in Example 1 §A, but starting from glycine (7.5 g), sodium bicarbonate (8.4 g) in water (150 cc) and methyl 3-isocyanatobenzoate (17.7 g). After treatment, 2-[3-(3-methoxycarbonyl-20 phenyl)ureido]acetic acid (14.5 g), m.p. 215°C, is obtained.

Example 94 The operation is carried out in a fashion similar to 218 that described in Example 9, but starting from tert-butyl (2S,5R)-l-{2-[3-(3-ethoxycarbonylphenyl-ureido]-acetyl}-5-phenylprolinate (2.6 g) in solution in methanol (40 cc) and potassium hydroxide (0.33 g) in solution in water (20 cc). After treatment, (2S,5R)-3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}benzoic acid (1.8 g), its analytical data being in agreement with those of the dextrorotatory enantiomer prepared by chiral stationary phase chromatography of the racemic product, is obtained. tert-Butyl (2S,5R)-l-{2-[3-(3-ethoxycarbonylphenyl)-ureido]acetyl}-5-phenylprolinate may be obtained as follows: starting from tert-butyl (2RS,5SR)-l-{2-[3-(3-ethoxycarbonylphenyl)ureido]acetyl}-5-phenylprolinate (6.6 g), high performance liquid chromatography on a support (400g), the preparation of which is described below, contained in a 26 cm long column of 6 cm diameter with, as mobile phase, a hexane/ethanol (70/30 by volume) mixture, is used to separate, at a rate of 70 cc per minute in sequential elution order: - tert-Butyl (2S,5R)-l-{2-[3-(3- ethoxycarbonylphenyl)ureido]acetyl}-5-phenylprolinate (2.9 g), the specific rotation of which is [a]" = +30 ± 0.8° (c = 0.922; methanol) tert-Butyl (2R,5S)-l-{2-[3-(3-ethoxycarbonylphenyl)-ureido]acetyl}-5-phenylprolinate (2.8 g), the specific 219 rotation of which is [a]" = -27 ± 0.6° (c methanol). = 1,213; Example 95 The operation is carried out in a fashion similar to that described in Example 9, but starting from tert-butyl (2S,5R)-l-{2~[3-(3-methoxycarbonylphenyl)ureido]-acetyl}-5-phenylprolinate (3.5 g) in solution in methanol (60 cc) and potassium hydroxide (0.45 g) in solution in water (30 cc). After treatment, (2S,5R)-3-{3-{2-(2-tert-butoxycarbonyl-5-phenyl-1-pyrrolidinyl)-2-oxoethyl}ureido} benzoic acid (2.0 g), the analytical data of which are in agreement with those of the dextrorotatory enantiomer prepared by chiral stationary phase chromatography of the racemic product, is obtained. (2S,5R)-l-{2-[3-(3-methoxycarbonylphenyl)ureido]-acetyl}-5-phenylprolinate may be prepared as described in Example 41 §A, but starting from tert-butyl (2S,5R)-5-phenylprolinate (0.1 g), 2-[3-(3-methoxycarbonyl-phenyl)ureido]acetic acid (0.1 g) and N,N'-dicyclo-hexylcarbodiimide (0.8 g) in tetrahydrofuran (5 cc). After treatment, (2S,5R)-l-<2-[3-(3-methoxycarbonyl-phenyl)ureido]acetyl}-5-phenylprolinate (1.0 g), the analytical data of which are in agreement with those of the dextrorotatory enantiomer prepared by chiral *" j "s r~ * '] l ' . i -? stationary phase chromatography of the racemic product, is obtained. tert-Butyl (2S,5R)-5-phenylprolinate may be prepared as follows: in the space of five minutes at a temperature in 5 the vicinity of 2°C, a solution of sodium boro-hydride (0.14 g) and of potassium carbonate (0.07 g) in water (0.8 cc) is added to an emulsion of tert-butyl (S)-5-phenyl-A5 -pyrroline-2-carboxylate (0.83 g) in a mixture of ethanol (0.5 cc) and of water (1.5 cc) . The reaction medium is 10 stirred for 20 hours at a temper-ature in the vicinity of 20°C, followed by the addition of a solution of sodium borohydride (0.14 g) and potassium carbonate (0.07 g) in water (0.8 cc). The reaction medium is stirred again for 70 hours at a temperature in the vicinity of 20°C, then 15 diluted with 25 cc of water and extracted with dichloromethane (3 x 20 cc). The organic extracts are combined, washed with water (10 cc), dried over magnesium sulphate and concentrated to dryness under reduced pressure at 50°C. The residue is purified by chromatography on 20 silica [eluent: dichloromethane]. The fractions containing the expected product are combined and concentrated under reduced pressure. tert-Butyl (2S,5R)-5-phenylprolinate (0.1 g) is thus obtained in the form of an oil used as it is in subsequent syntheses. tert-Butyl (S)-5-phenyl-^5-pyrroline-2-carboxylate may 221 be prepared as follows: at a temperature in the vicinity of 2 0"C trifluoroacetic acid (2.3 cc) is added to a solution of tert-butyl (S)-2-tert-butoxycarbonyl-amino-5-oxo-5-phenylpentanoate (1.8 g) in 5 dichloromethane (25 cc). The reaction mixture is stirred for six hours at a temperature in the vicinity of 20 °C, with the subsequent addition of a saturated aqueous sodium bicarbonate solution (120 cc). The organic phase is separated by decantation, washed with 10 distilled water (20 cc), dried over magnesium sulphate and concentrated under reduced pressure. tert-Butyl (S)-5-phenyl-a5-pyrroline-2-carboxylate (0.9 g) is thus obtained in the form of an oil, used as it is in subsequent syntheses. tert-Butyl (S)-2-tert-butoxycarbonylamino-5-oxo-5-phenylpentanoate may be prepared as follows: in the space of 35 minutes at a temperature of between 20 and 30°C a solution of bromobenzene (2.8 cc) in tetrahydrofuran (60 cc) is added to a suspension of 20 magnesium (0.72 g) in tetrahydrofuran (20 cc). The reaction medium is then stirred at a temperature in the vicinity of 24°C for 145 minutes, with the subsequent addition in the space of 20 minutes of a solution of tert-butyl (S)-l-tert-butoxycarbonyl-5-oxopyrrolidine-25 2-carboxylate (5.7 g) in tetrahydrofuran (80 cc) kept at a temperature in the vicinity of -75°C. The reaction medium is stirred for another three hours at a 222 temperature in the vicinity of -78°C, then reheated to a temperature in the vicinity of -15°C. A 10% aqueous ammonium chloride solution (100 cc) is then added in the space of 15 minutes. The aqueous phase is separated by decantation and extracted with diethyl ether (3 x 100 cc). The organic phases are combined and washed with water (2 x 25 cc), dried over magnesium sulphate and concentrated under reduced pressure at a temperature in the vicinity of 50°C. The residue is purified by crystallisation in pentane (20 cc). tert-Butyl (S) -2-tert-butoxycarbonylamino-5-oxo-5-phenyl-pentanoate (2.5 g) , m.p. 107°C, is thus obtained. This product may also be present in the form of tert-butyl (2S,5RS)-l-tert-butoxycarbonyl-5-hydroxy-5-phenyl-pyrrolidine-2-carboxylate, m.p. 85°C. tert-Butyl (S)-l-tert-butoxycarbonyl-5-oxopyrrolidine-2-carboxylate may be obtained according to the method described by J. ACKERMANN and M. MATTHES, Helv. Chim. Acta, 73, 122-132, (1990). tert-Butyl ( 2S,5R)-l-{2-[3-(3-methoxycarbonylphenyl)-ureido]acetyl}-5~phenylprolinate may also be obtained as follows: starting from tert-butyl (2RS,5SR)-l-{2-[3-(3-methoxycarbonylphenyl) ureido ] acetyl} -5-phenylprolinate (7.8 g), high performance liquid chromatography on a support (400 g), the preparation of which is described in the preceding example, contained in a 26 cm long column of 6 cm diameter, with, as mobile phase, a hexane/ethanol (70/30 by volume) z r . 4 223 mixture, is used to separate at a rate of 70 cc per minute rate in sequential elution order: tert-Butyl (2S,5R)-l-{2-[3-(3-methoxycarbonylphenyl )ureido]acetyl>-5-phenylprolinate (3.7 g), the 5 specific rotation of which is [a]l° = +31.4 t 1.2° (c = 0.579; methanol) - tert-Butyl (2R,5S)-l-{2-[3-(3-methoxycarbonylphenyl) ureido ] acetyl }-5-phenylprolinate (3.6 g), the specific rotation of which is [a]" = +28.2 10 ± 0.8° (c = 0.949; methanol).

Example 96 The operation is carried out in a fashion similar to that described in Example 9, but starting from tert-butyl (2R,5S)-l-{2-[3-(3-15 ethoxycarbonylphenyl)ureido]acetyl)-5-phenylprolinate (2.6 g) in solution in methanol (60 cc) and potassium hydroxide (0.3 g) in solution in water (40 cc). After treatment, (2R,5S)-3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl)-1-pyrrolidinyl)-2-oxoethyl]ureido)benzoic acid 20 (1.3 g), the analytical data of which are in agreement with those of the levorotatory enantiomer prepared by chiral stationary phase chromatography of the racemic product, is obtained. 2 4 3 ^ 14 224 Example 97 The operation is carried out in a fashion similar to that described in Example 9, but starting from tert-butyl (2R,5S)-l-{2-[3-(3-methoxycarbonylphenyl)-5 ureido]acetyl}-5-phenylprolinate (3.38 g) in solution in methanol (60 cc) and potassium hydroxide (0.45 g) in solution in water (20 cc). After treatment, (2R,5S)-3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl)-1-pyrrolidinyl)-2-oxoethyl]ureido}benzoic acid (2.0 g), the analytical 10 data of which are in agreement with those of the levorotatory enantiomer prepared by chiral stationary phase chromatography of the racemic product, is obtained.

Example 98 The operation is carried out as in Example 9, but starting from methyl (2S,5R)-3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}phenylacetate (1.9 g) in solution in methanol (60 cc) and potassium hydroxide (0.22 g) 20 dissolved in water (30 cc). After treatment, (2S,5R)-3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}phenylacetic acid (0.65 g), m.p. 112°C, [a]" = +30. 68 + 0.8° (c = 1; methanol) is obtained. 225 Methyl (2S,5R)-3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-1-pyrrolidinyl)-2-oxoethyl]ureido}pnenylacetate may be prepared as described in Example 41 §A, but starting from tert-butyl (2S,5R)-5-phenylprolinate (1.2 g), 2-[3-(3-methoxycarbonylmethylphenyl)ureido]acetic acid (1.29 g) and N,N'-dicyclohexylcarbodiimide (1 g) in acetonitrile (50 cc). After treatment, methyl (2S,5R)-3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-1-pyrrolidinyl)-2-oxoethyl]ureido}phenylacetate (1.9 g) is obtained in the form of a meringue-like product, used as it is in subsequent syntheses. tert-Butyl (2S,5R)-5-phenylprolinate may be prepared as follows: platinum oxide (0.02 g) is added to a solution of tert-butyl (S)-5-phenyl-a5-pyrroline-2-carboxylate (1.25 g) in ethanol (50 cc). The suspension is stirred for 3 hours at a temperature in the vicinity of 20°C under a hydrogen atmosphere (130 kPa). The catalyst is separated by filtration and the filtrate is concentrated to dryness under reduced pressure at 45°C. The residue is purified by chromatography on silica [eluent: dichloromethane/methanol (97.5/2.5 by volume)]. The fractions containing the expected product are combined and concentrated under reduced pressure. tert-Butyl (2S,5R)-5-phenylprolinate (1.2 g) is thus obtained in the form of an oil used as it is in subsequent syntheses. ft » * 226 tert-Butyl (S)-5-phenyl-A5-pyrroline-2-carboxylate may be prepared as follows: at a temperature in the vicinity of 20°C, iodotrimethylsilane (1.4 cc) is added to a solution of tert-butyl (S)-2-tert-5 butoxycarbonylamino-5-oxo-5-phenylpentanoate (3.65 g) in dichloromethane (50 cc). The reaction mixture is stirred for 20 hours at a temperature in the vicinity of 20°C, with subsequent addition of a saturated aqueous sodium bicarbonate solution (50 cc). The 10 organic phase is separated by decantation, washed with distilled water (20 cc), dried over magnesium sulphate and concentrated under reduced pressure. tert-Butyl (S)-5-phenyl-a5-pyrroline-2-carboxylate (2.0 g) is thus obtained in the form of an oil used as it is in 15 subsequent syntheses.

Example 99 The operation is carried out in a fashion similar to that described in Example 2, but starting from tert-butyl (2RS,5SR)-l-(2-aminoacetyl) -5-phenylprolinate 20 (1.93 g) and benzyl 3-isocyanatobenzoate (3.61 g) in tetrahydrofuran (50 cc). After treatment, tert-butyl (2RS,5SR)-l-{2-[3-(3-benzyloxycarbonylphenyl)-ureido]acetyl)-5-phenylprolinate (1 g), m.p. 75°C, is obtained.

Benzyl 3-isocyanatobenzoate may be prepared as described in Example 64 §A, but starting from benzyl 3-aminobenzoate hydrochloride (27 g) in toluene (200 cc), triethylamine (14.4 cc), charcoal (2 g) and trichloromethyl chloroformate (12.5 cc) in toluene (200 cc). After 5 treatment, benzyl 3-isocyanatobenzoate (27 g) is obtained in the form of an oil, used as it is in subsequent syntheses.

Benzyl 3-aminobenzoate may be prepared according to the method described by H.A. SHONLE et al., J. Amer. Chem. 10 Soc., 43, 361 (1921).

Example 100 Palladized charcoal (0.5 g/5%) is added to a solution of ethyl (2RS,5SR)-l-{2-[3-(3-benzyloxycarbonylphenyl)-ureido]acetyl}-5-phenylprolinate (1.7 g) in ethanol (100 15 cc). The suspension is stirred for 20 hours at a temperature in the vicinity of 25°C under a hydrogen atmosphere (130 kPa). The catalyst is separated by filtration and the filtrate is concentrated to dryness under reduced pressure. The residue is recrystallised in 20 ethanol (80 cc). (2RS,5SR)-3-{3-[2-(2-Ethoxy-carbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]-ureido}benzoic acid (0.7 g), m.p. 240°C, is thus obtained.

Ethyl (2RS,5SR)-l-{2-[3-(3-benzyloxycarbonylphenyl)- L.. -ir J 228 ureido]acetyl}-5-phenyl-prolinate may be prepared as described in Example 41 §A, but starting from ethyl (2RS,5SR)-5-phenylprolinate (2 g), 2-[3—(3— benzyloxycarbonylphenyl]ureido]acetic acid (2.99 g) and 5 N,N'-dicyclohexylcarbodiimide (2.07 g) in tetrahydrofuran (180 cc). After treatment, ethyl (2RS,5SR)-l-{2-[3-(3-benzyloxycarbonylphenyl)-ureido]acetyl>-5-phenylprolinate (1.95 g) is obtained in the form of a meringue-like product, used as it is 10 in subsequent syntheses. 2-[3-(3-benzyloxycarbonylphenyl)ureido]acetic acid may be prepared as described in Example 1 §A, but starting from glycine (3.97 g) and potassium carbonate (14.62 g) in solution in water (90 cc) and benzyl 3-isocyanato-15 benzoate (13.4 g) in solution in 1,4-dioxane (70 cc). After treatment, 2-[3-(3-benzyloxycarbonylphenyl)-ureido]acetic acid (13 g), used as it is in subsequent syntheses, is obtained.

Ethyl (2RS,5SR)-5-phenylprolinate may be obtained as 20 follows: concentrated sulphuric acid (0.5 cc) is added dropwise to a solution of (2RS,5SR)-5-phenylproline (5.5 g) in ethanol (50 cc). The reaction mixture is then stirred at a temperature in the vicinity of 80"C for five hours, then cooled to a temperature in the 25 vicinity of 20°C and concentrated under reduced pressure. The residue is taken up in water (50 cc), 24 3 5 229 brought to a pH in the vicinity of 9 by a normal aqueous sodium hydroxide solution and extracted with ethyl acetate (3 x 100 cc). The combined organic extracts are washed with saturated aqueous sodium 5 chloride solution (50 cc), dried over magnesium sulphate and concentrated under reduced pressure. The residue is subjected to chromatography on silica [eluent cyclohexane/ethyl acetate (90/10 by volume)]. The fractions containing the expected product are 10 combined and concentrated under reduced pressure. Ethyl (2RS,5SR)-5-phenylprolinate (2.16 g) is thus obtained in the form of an oil, used as it is in subsequent syntheses.

Example 101 The operation is carried out in a fashion similar to that described in Example 100, but starting from tert-butyl (2RS,5SR)-l-{2-[3-(3-benzyloxycarbonylphenyl)-ureido]acetyl)-5-phenylprolinate (10.2 g) and 5% palladium on charcoal (1 g) in ethanol (300 cc). After 20 treatment, (2RS,5RS)-3-{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}benzoic acid (7.1 g), m.p. 236°C, is obtained.

Example 102 The operation is carried out in a fashion similar to 230 that described in Example 100, but starting from tert-butyl (2RS, 5RS)—1 — -{2 — [3—(3-benzyloxycarbonylphenyl) -ureido]acetyl}-5-phenylprolinate (0.8 g) in solution in ethyl acetate (50 cc) and 5% palladium on charcoal (0.1 g). After treatment, (2RS,5SR)-3-{3-{2-[2-tert-butoxy-carbonyl-5- (3-methylphenyl) -1-pyrrolidinyl ] -2-oxoethyl}ureido}benzoic acid (0.45 g), m.p. 208°C, is obtained. tert-Butyl (2RS,5RS)-l-{2-[ 3-(3-benzylcarbonylphenyl)-ureido]acetyl}-5-phenylprolinate may be prepared as described in Example 41 §A, but starting from tert-butyl (2RS,5SR)-5-(3-methylphenyl)-prolinate (0.4 g), 2-[ 3-(3-benzyloxycarbonylphenyl)-ureido]acetic acid (0.5 g) and N,N'-dicyclohexyl-carbodiimide (0.31 g) in acetonitrile (20 cc). After treatment, tert-butyl (2RS, 5RS) -1- { 2 - [ 3 - (3-benzyloxycarbonylphenyl) ureido ] -acetyl}-5-phenylprolinate (0.8 g) is obtained in the form of a meringue-like product, used as it is in the subsequent syntheses. tert-Butyl (2RS,5SR)-5-(3-methylphenyl)prolinate may be prepared as described in Example 2 SA, but starting from tert-butyl (2RS,5SR)-l-tert-butoxycarbonyl-5-(3-methylphenyl)prolinate (1 g) and iodotrimethylsilane (0.4 cc) in chloroform (40 cc). After treatment, tert-butyl (2RS,5SR)-5-(3-methylphenyl)prolinate (0.4 g) is 231 obtained in the form of an oil, used as it is in subsequent syntheses. tert-Butyl (2RS,5SR)-l-tert-butoxycarbonyl-5-(3-methylphenyl)prolinate may be prepared as described in 5 Example 90 §A, but starting from sodium dihydrogen phosphate (2.4 g) and 6% sodium amalgam (7.63 g) (in mercury) in a solution of a mixture (2.5 g) of the two 4-position epimers of tert-butyl (2RS,5RS)-l-tert-butoxycarbonyl-5- ( 3-methylphenyl)-4-phenylsulphonyl-10 prolinate in a mixture of methanol (20 cc) and of tetrahydrofuran (40 cc). After treatment, tert-butyl (2RS,5SR)-l-tert-butoxycarbonyl-5-(3-methylphenyl)-prolinate (1 g) is obtained in the form of an oil, used as it is in subsequent syntheses. tert-Butyl (2RS,5RS)-l-tert-butoxycarbonyl-5-(3-methylphenyl)-4-phenylsulphonylprolinate may be prepared as follows: sodium bicarbonate (0.42 g) and then a solution of di-tert-butyl dicarbonate (1.09 g) in dichloromethane (20 cc) are added successively to a 20 solution of a mixture (2.01 g) of the two 4-position epimers of tert-butyl (2RS,5RS)-5-(3-methylphenyl)-4-phenylsulphonylprolinate in dichloromethane (50 cc). The reaction mixture is stirred for 72 hours at a temperature in the vicinity of 20°C, with the 25 subsequent addition of water (50 cc). The organic phase is separated by decantation, dried over magnesium 232 sulphate and concentrated to dryness under reduced pressure. tert-Butyl (2RS,5RS)-l-tert-butoxycarbonyl-5-(3-methylphenyl)-4-phenylsulphonylprolinate (2.5 g) (mixture of the two 4-position epimers), is thus 5 obtained in the form of an oil, used as it is in subsequent syntheses. tert-Butyl (2RS,5RS)-5-(3-methylphenyl)-4-phenylsulphonylprolinate may be prepared as described in Example 89 §A, but starting from tert-butyl N-(meta-10 methylbenzylidene)glycinate (4.7 g), silver acetate (5 g), phenyl vinyl sulfone (3.4 g) and triethylamine (2.8 cc). After treatment, tert-butyl (2RS,5RS)-5-(3-methylphenyl)-4-phenylsulphonyl-prolinate (6.1 g) , a mixture of the two 4-position epimers, m.p. 139°C, is 15 obtained. tert-Butyl (N-(meta-methylbenzylidene) glycinate may be prepared as described in Example 89 SB, but starting from meta-tolualdehyde (2.4 cc), tert-butyl glycinate hydrochloride (3.35 g), triethylamine (2.8 cc) and 4k 20 molecular sieve (3 g) in dichloromethane (30 cc). After treatment, tert-butyl (N-(meta-methylbenzylidene) glycinate (4.7 g) is obtained in the form of an oil, used as it is in subsequent syntheses. 233 Example 103 The operation is carried out in a fashion similar to that of Example 9, but starting from a mixture of tert-butyl (2RS,3SR)- and (2RS,3RS)-l-{2-[3-(3-ethoxy-5 carbonylphenyl)ureido]acetyl}-3-phenylprolinate} (1.2 g), in a weight ratio of 85 to 15 in solution in tetrahydrofuran (30 cc) in normal sodium hydroxide solution (2.4 cc) diluted with water (15 cc). After treatment, a mixture of (2RS,3SR)- and (2RS,3RS)-3-{3-10 [2-(2-tert-butoxycarbonyl-3-phenyl-1-pyrrolidinyl)-2- oxoethyl]ureido}benzoic acid (0.7 g), in a weight ratio of 85 to 15, m.p. 225°C, is obtained. tert-Butyl (2RS,3SR)-l-{2-[3-(3-ethoxycarbonylphenyl)-ureido]acetyl)-3-phenylprolinate may be prepared as 15 described in Example 41 §A, but starting from a mixture of tert-butyl (2RS,3SR)- and (2RS,3RS)-3-phenylprolinate (1 g), in a weight ratio of 85 to 15, of 2-[3-(3-ethoxycarbonylphenyl)ureido]acetic acid (1.1 g) and of N,N'-dicyclohexylcarbodiimide (0.83 g) 20 in tetrahydrofuran (30 cc). After treatment, a mixture of tert-butyl (2RS,3SR)- and (2RS,3RS)-l-{2-[3-(3-ethoxycarbonylphenyl)ureido] acetyl)-3-phenylprolinate (1.2 g) in a weight ratio of 85 to 15, m.p. 154°C, is obtained. f ( * :? ' 234 tert-Butyl (2RS,3SR)-3-phenylprolinate and (2RS,3RS)-3-phenylprolinate may be prepared as described in Example 1 §B, but starting from a mixture of (2RS,5SR)- and (2RS,5RS)-3-phenylproline (10 g), isobutene and 5 sulphuric acid (3 cc) in chloroform (200 cc). After treatment and chromatography on silica [eluent cyclohexane/ethyl acetate (50/50 by volume)], a mixture of tert-butyl (2RS,3SR)- and (2RS,3RS)-3-phenylprolinate (1 g), in a weight ratio of 85 to 15, in the form of an oil used as it is in subsequent syntheses, and a mixture of tert-butyl (2RS,3RS)- and (2RS,3SR)-3-phenylprolinate (2.5 g), in a weight ratio of 85 to 15, in the form of an oil, used as it is in subsequent syntheses, are obtained.

The (2RS,5SR)- and (2RS,5RS)-3-phenylprolines may be prepared by the methods described by Y. N. BELOKON et al., J. Chem. Soc., Perkin Trans., 1, 2075 (1988) and J. RIVIER., G. R. MARSHALL Peptides, Chemistry, Structure and Biology, Proceedings of the Eleventh 20 American Peptide Symposium, July 9-14 1989, La Jolla, California, USA, ESCOM, Leiden, 1990.

Example 104 The operation is carried out in a fashion similar to that described in Example 9, but starting from a 25 mixture of tert-butyl (2RS,3RS)- and (2RS,3SR)-l-{2-[3- 235 (3-ethoxycarbonylphenyl)ureido]acetyl}-3-phenyl-prolinate (2.5 g), in a weight ratio of 80 to 20, in solution in tetrahydrofuran (30 cc) and a normal sodium hydroxide solution with (5 cc) diluted water (15 cc). 5 After treatment, a mixture of (2RS,3RS)- and (2RS,3SR)-3-{3-[2-(2-tert-butoxycarbonyl-3-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}benzoic acid (1 g), in a weight ratio of 90 to 10, m.p. 200°C, is obtained. tert-Butyl (2RS,3RS)-l-{2-[3-(3-ethoxycarbonylphenyl)-10 ureido]acetyl}-3-phenylprolinate may be prepared as described in Example 41 §A, but starting from a mixture of tert-butyl (2RS,3RS)- and (2RS,3SR)-3-phenylprolinate (2.5 g), in a weight ratio of 90 to 10, 2 —[3 — (3-ethoxycarbonylphenyl)ureido]acetic acid (2.7 g), and 15 N,N'-dicyclohexylcarbodiimide (2.1 g) in tetrahydrofuran (50 cc). After treatment, a mixture of tert-butyl (2RS,3RS)- and (2RS, 3SR)-l-{2-[3-(3-ethoxycarbonylphenyl)ureido]acetyl}-3-phenylprolinate (1.2 g), in a weight ratio of 80 to 20, m.p. 141°C, is 20 obtained.

Example 105 The operation is carried out in a fashion similar to that described in Example 9, but starting from tert-butyl (2S,4S) -l-{2-[3-(3-methoxycarbonylphenyl)-25 ureido]acetyl}-4-phenylprolinate (2.1 g) in solution in 236 methanol (30 cc) and potassium hydroxide (0.5 g) dissolved in water (15 cc). After treatment and crystallisation in a diisopropyl ether/diisopropyl acetate (90/10 by volume) mixture, (2S,4S)-3-{3-[2-(2-5 tert-butoxycarbonyl-4-phenyl-l-pyrrolidinyl)-2- oxoethyl]ureido}benzoic acid (0.65 g), m.p. 144"C, is obtained. tert-Butyl (2S,4S)-l-{2-[3-(3-methoxycarbonylphenyl)-ureido]acetyl}-4-phenylprolinate may be prepared as 10 described in Example 41 §A, but starting from tert-butyl (2S,4S)-4-phenylprolinate (1.2 g), 2-[3-(3-methoxycarbonylphenyl)ureido]acetic acid (1.2 g) and N,N'-dicyclohexylcarbodiimide (1 g) in acetonitrile (30 cc). After treatment, tert-butyl (2S,4S)-l-{2-[3-15 (3-methoxycarbonylphenyl)ureido]acetyl}-4- phenylprolinate (2.1 g) is obtained in the form of a meringue-like product, used as it is in subsequent syntheses. tert-Butyl (2S,4S)-4-phenylprolinate may be prepared as 20 described in Example 1 SB, but starting from (2S,4S)-4-phenylproline (3.4 g), isobutene and sulphuric acid (1.5 cc) in chloroform (150 cc). After treatment, tert-butyl (2S,4S)-4-phenylprolinate is obtained in the form of a meringue-like product, used as it is in subsequent 25 syntheses. 237 (2S,4S)-4-phenylproline may be prepared according to the methods described by J. K. THOTTATHIL and J. L. MONIOT, Tetrahedron Lett., 27, 151 (1968) and D.R. KRONENTHAL et al., Tetrahedron Lett., 31, 1241 (1990).

Example 106 The operation is carried out in a fashion similar to that described in Example 9, but starting from tert-butyl (2S, 4R)-1-(2-[3-(3-methoxycarbonylphenyl)-ureido]acetyl)-4-phenylprolinate (1.8 g) in solution in. 10 methanol (30 cc) and potassium hydroxide (0.21 g) dissolved in water (15 cc). After treatment and crystallisation in a diisopropyl ether/diisopropyl acetate (90/10 by volume) mixture, (2S,4R)-3-{3-[2-(2-tert-butoxycarbonyl-4-phenyl-l-pyrrolidinyl)-2-15 oxoethyl]ureido)benzoic acid (0.55 g), m.p. 140'C, is obtained. tert-Butyl (2S, 4R)-l-{2-[3-(3-methoxycarbonylphenyl)-ureido]acetyl)-4-phenylprolinate may be prepared as described in Example 41 §A, but starting from tert-20 butyl (2S,4R)-4-phenylprolinate (1 g), 2-[3-(3- methoxycarbonylphenyl)ureido]acetic acid (1 g) and N,N'-dicyclohexylcarbodiimide in acetonitrile (30 cc). After treatment, tert-butyl (2S,4R)-l-{2-[3-(3-methoxycarbonylphenyl)ureido]acetyl}-4-phenylprolinate 25 (1.8 g) is obtained in the form of a meringue-like L <* 238 product, used as it is in subsequent syntheses. tert-Butyl (2S,4R)-4-phenylprolinate may be prepared as described in Example 1 §B, but starting from (2S,4R)-4-phenylproline (4.4 g), isobutene and sulphuric acid 5 (1.5 cc) in chloroform (150 cc). After treatment, tert-butyl (2S,4R)-4-phenylprolinate (1 g), m.p. 62°C, is obtained. (2S,4R)-4-phenylproline may be prepared according to the methods described by J. K. THOTTATHIL and J. L. 10 MONIOT, Tetrahedron Lett., 27, 151 (1968) and D.R.

KRONENTHAL et al., Tetrahedron Lett., 31, 1241 (1990).

Example 107 The operation is carried out in a fashion similar to that described in Example 9, but starting from tert-15 butyl (2RS,5SR)-l-{2-[3-(3-benzyloxycarbonylphenyl)-ureido]acetyl}-5-(2-pyridyl)prolinate (0.55 g) in solution in methanol (20 cc) and 0.1 N aqueous potassium hydroxide solution (10 cc) . After treatment, (2RS,5SR)-3-{3-[2- (2-tert-butoxycarbonyl-5-(2-pyridyl)-20 1-pyrrolidinyl)-2-oxoethyl]ureido}benzoic acid (0.17 g), m.p. 174°C, is obtained. tert-Butyl (2RS,5SR)-1-{2-[3-(3-benzyloxycarbonyl-phenyl)ureido]acetyl}-5-(2-pyridyl)prolinate may be iTi * ■X- " y* 239 prepared as described in Example 2, but starting from tert-butyl (2RS,5SR)-1-(2-aminoacetyl)-5-(2-pyridyl)-prolinate (0.5 g) and benzyl 3-isocyanatobenzoate (0.45 g) in tetrahydrofuran (25 cc). After treatment, tert-butyl (2RS,5SR)-l-{2-[3-(3-benzyloxycarbonylphenyl) ureido] acetyl >-5- (2-pyridyl) prolinate (0.7 g) is obtained in the form of a meringue-like product, used as it is in subsequent syntheses. tert-Butyl (2RS,5SR)-l-(2-aminoacetyl)-5-(2-pyridyl)prolinate may be prepared as described in Example 2 §A, but starting from tert-butyl (2RS,5SR)-1-(2-tert-butoxycarbonylaminoacetyl)-5-(2-pyridyl)-prolinate (0.7 g) and iodotrimethylsilane (0.25 cc) in chloroform (30 cc). After treatment, tert-butyl (2RS,5SR)-l-(2-aminoacetyl)-5-(2-pyridyl)prolinate (0.5 g) is obtained in the form cf an oil, used as it is in subsequent syntheses. tert-Butyl (2RS,5SR)-1-(2-tert-butoxycarbonylamino-acetyl)-5-(2-pyridyl)prolinate may be prepared as described in Example 90 §A, but starting from sodium dihydrogen phosphate (4.8 g) and 6% sodium amalgam (15.3 g) (in mercury) in a solution of a mixture (5.5 g) of the two 4-position epimers of tert-butyl (2RS,5RS)-1-(2-tert-butoxycarbonylaminoacetyl)-4-phenylsulphonyl-5-(2-pyridyl)prolinate in a mixture of methanol (20 cc) and of tetrahydrofuran (60 cc). After 240 treatment, tert-butyl (2RS,5SR)-l-(2-tert-butoxycarbonylaminoacetyl)-5-(2-pyridyl)prolinate (0.7 g) is obtained in the form of an oil, used as it is in subsequent syntheses. tert-Butyl (2RS,5RS)-l-(2-tert-butoxycarbonylamino- acetyl)-4-phenylsulphonyl-5-(2-pyridyl)prolinate may be prepared as follows: ethyl chloroformate (1.5 cc) is added to a solution of 2-tert-butoxycarbonylamino-acetic acid (2.7 g) in a mixture of triethylamine 10 (2.2 cc) and of dichloromethane (100 cc) maintained at a temperature in the vicinity of 0°C. The reaction medium is stirred for thirty minutes at a temperature in the vicinity of 0°C with a subsequent addition of a solution of tert-butyl (2RS,5RS)-4-phenylsulphonyl-5-15 (2-pyridyl)prolinate (6 g) in dichloromethane (50 cc). The reaction mixture is stirred for twenty hours at a temperature in the vicinity of 20°C, with a subsequent addition of water (100 cc). The organic phase is separated by decantation, washed with water (25 cc), 20 dried over magnesium sulphate and concentrated under reduced pressure. The residue is purified by chromatography on silica [eluent: cyclohexane/ethyl acetate (50/50 by volume)]. The fractions containing the expected product are combined and concentrated 25 under reduced pressure. tert-Butyl (2RS,5RS)-l-(2-tert-butoxycarbonylaminoacetyl)-4-phenylsulphonyl-5-(2-pyridyl)prolinate (5.6 g) (mixture of the two 4- l-\ 0 0 241 position epimers) is thus obtained in the form of an oil, used as it is in subsequent syntheses. tert-Butyl (2RS,5RS)-4-phenylsulphonyl-5-(2-pyridyl)prolinate may be prepared as described in 5 Example 89 SA, but starting from tert-butyl N-[(2-pyridyl)methylene]glycinate (4.4 g), silver acetate (5 g), phenyl vinyl sulphone (3.4 g) and triethylamine (2.8 cc) in acetonitrile (200 cc). After treatment, tert-butyl (2RS,5RS)-4-phenylsulphonyl-5-(2-10 pyridyl)prolinate (6 g) (mixture of the two 4-position epimers) is obtained in the form of an oil, used as it is in the subsequent syntheses. tert-Butyl N-[(2-pyridyl)methylene]glycinate may be prepared as described in Example 89 SB, but starting 15 from 2-pyridylcarboxaldehyde (1.4 cc), tert-butyl glycinate hydrochloride (3.35 g), triethylamine (2.8 cc) and 4A molecular sieve (3 g) in dichloromethane (30 cc). After treatment, tert-butyl N-[(2-pyridyl)methylene]glycinate (4.8 g) is obtained in 20 the form of an oil, used as it is in subsequent syntheses. 242 Example 108 Oxone® (1.3 g) in solution in distilled water (8 cc) is added to a solution of 2-{3-{3-(2-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-5 oxoethyl}ureido}phenyl}-propionic acid (A form) (0.65 g) in methanol (6 cc). The reaction medium is stirred for 12 hours at a temperature in the vicinity of 25 °C, then concentrated under reduced pressure at 40°C. The product obtained is purified by chromato-10 graphy on silica [eluent: methylene chloride/methanol (90/10 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. 2-{3-{3-(2-[(IRS,2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-15 l-oxide-3-thiazolidinyl]-2-oxoethyl>-ureido}phenyl}- propionic acid (A form) (0.4 g) is thus obtained in the form of an amorphous product.

Proton NMR (200 MHz, DMSO D6, 6 in ppm, J in Hz); at 120°C the mixture of the two diastereoisomers in the 20 proportions 85-15 is observed, characteristic chemical shifts at 120°C: 1.32 (d, J = 7.5, 3H, -CH3); 1.50 and 1.58 (2s, 9H in total, -C(CH3)3 of the preponderant isomer, then of the less abundant isomer); 2.85 (t, J = 12.5, 0.85H, 1H of -S-CH2 for the preponderant 25 isomer); 3.4 to 4.4 (m, 6.15H, -CH-COO, the other H S •* 243 of -S-CH2 for the preponderant isomer, the -S-CH2 of the less abundant isomer and N-COCH2-N); 4.8 (t, J = 8, 0,15H, S-CH-N of the less abundant isomer); 4.97 (dd, J = 12.5 and 5.0, 0.85H, S-CH-N of the preponderant 5 isomer); 6.3 to 6.45 (m, 1H, -NHCO-); 6.5 and 6.6 (2s, 0.15H and 0.85H, S-CH-N of the less abundant isomer and of the preponderant isomer); 6.8 (bd, J = 8, 1H, in position 4 on CO-NH-Ph-); 7.0 to 7.6 (m, 6H, aromatic); 7.77 and 8.10 (t, J = 8, 0.15H and 0.85H, in position 6 10 on S-CH-Ph- for the less abundant isomer and for the preponderant isomer); 8.84 and 8.96 (2s, 0.85H and 0.15H, ArNHCO- for the preponderant isomer and for the less abundant isomer).

Infrared spectrum (KBr), characteristic bands in cm"1: 15 3390, 3100 to 3000, 2975, 2930, 2875 to 2300 (wide band), 1735, 1670, 1615, 1595, 1555, 1490, 1460, 1400, 1395, 1370, 1150, 760, 700.

Example 109 The operation is carried out in a fashion 20 similar to that described in Example 41, but starting from 2-trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(1-naphthyl)-3-thiazolidinylJ-2-oxoethyl>ureido}benzoate (1.85 g) and a 1M tetrabutyl-ammonium fluoride solution (5.82 cc). (2R,4R)-3-{3-{2-25 [4-tert-Butoxycarbonyl-2-(1-naphthyl)~3-thiazolidinyl]- ;• c: 244 2-oxoethyl}ureido}benzoic acid (0.47 g) is thus obtained in the form of a beige solid, m.p. 210°C. [a]" = +222 ±5° (C = 0.5 %; CHC13) .

Proton NMR (200 MHz, DMSO D6 plus several 5 drops of CDjCOOD, 5 in ppm, J in Hz), 2 rotamers at room temperature, characteristic chemical shifts at 120°C: 1.53 (s, 9H, -C(CH3)3); 3.25 (dd, J = 12 and 7, 1H, 1H of S-CH2); 3.49 (dd, J = 12 and 6.5, 1H, the other H of S-CH2); 3.7 (bd, J = 17.5, 1H, 1H of N-C0CH2-N) ; 4.08 10 (d, J = 17.5, 1H, the other'H of N-COCH2-N); 5.02 (dd, J = 7.0 and 6.5, 1H, N-CH-COO); 7.08 (s, 1H, S-CH-N); 7.15 to 8.15 (m, 11H, aromatic).

Infrared spectrum (KBr), characteristic bands in cm"1: 3390, 3100 to 3000, 2975, 2930, 1735, 1655, 15 1595, 1555, 1510, 1485, 1400, 1370, 1150, 785, 770. 2-Trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(1-naphthyl)-3-thiazolidinyl]-2-oxoethyl}ureido}benzoate may be prepared in a fashion similar to that described in Example 34, but starting 20 from tert-butyl (2R,4R)-3-(2-aminoacetyl)-2-(l-naphthyl)-4-thiazolidinecarboxylate (2.4 g) and 2-trimethylsilylethyl 3-isocyanatobenzoate (2.1 g). The crude product is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. 25 The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. 2-Trimethylsilyl (4R)-3-{3-{2-[4- 245 tert-butoxycarbonyl-2-(1-naphthyl)-3-thiazolidinyl]-2-oxoethyl>ureido}benzoate (A form) (1.85 g) is thus obtained in the form of a beige paste, used as it is in subsequent syntheses. tert-Butyl (2R,4R)-3-(2-aminoacetyl)-2-(1-naphthyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 34 A, but starting from tert-butyl (2R,4R)-3-(2-tert-butoxycarbonylamino-acetyl)-2-(1-naphthyl)-4-thiazolidinecarboxylate (3.65 g) and iodotrimethylsilane (1.13 cc). (2R,4R)-3-(2-Aminoacetyl)-2-(1-naphthyl)-4-thiazolidinecarboxylate (2.34 g) is thus obtained in the form of a yellow solid, used as it is in subsequent syntheses. tert-Butyl (2R,4R)-3-(2-tert-butoxycarbonyl aminoacetyl)-2-(1-naphthyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 34 B, but starting from tert-butyl (2RS,4R)-2-(1-naphthyl)-4-thiazolidinecarboxylate (7.54 g), 2-tert-butoxycarbonylaminoacetic acid (4.23 g) and N,N'-dicyclohexylcarbodiimide (4.98 g). The crude product is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure. tert-Butyl (2R,4R)-3-(2-tert-butoxycarbonylaminoacetyl)-2-(1-naphthyl)-4-thiazolidinecarboxylate (13.9 g) is thus 246 obtained in the form of an orange oil, used as it is in subsequent syntheses. tert-Butyl (2RS,4R)-2-(1-naphthyl)-4-thiazolidinecarboxylate may be prepared in a fashion 5 similar to that described in Example 34 C, but starting from (2RS,4R)-2-(1-naphthyl)-4-thiazolidinecarboxylic acid (20.0 g) in solution in chloroform (300 cc), concentrated sulphuric acid (5.8 cc) and an excess of isobutene. The crude product obtained is purified by 10 chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the. expected product are combined and concentrated to dryness under reduced pressure at 40°C. tert-Butyl (2RS,4R)-2-(1-naphthyl)-4-thiazolidinecarboxylate 15 (10.15 g) is thus obtained in the form of an orange oil, a mixture of the (2R,4R) and (2S,4R) isomers, used as it is in subsequent syntheses. (2RS,4R)-2-(1-naphthyl)-4-thiazolidinecarboxylic acid may be prepared as in Example 34 D, but 20 starting from L-cysteine (20.0 g) and 1-naphthyl- carboxaldehyde (28.5 g). (2RS,4R)-2-(1-naphthyl)-4-thiazolidinecarboxylic acid (36.3 g), m.p. 208°C, used as it is in subsequent syntheses, is thus obtained.

Example 110 The operation is carried out in a fashion similar to that described in Example 41, but starting 1 4 247 from 2-trimethylsilylethyl (4R)-3-{3-{2-[4-tert-butoxy-carbonyl-2-(5-methyl-2-thienyl)-3-thiazolidinyl]-2-oxoethyl}ureido}benzoate (A form) (0.12 g) and 1M tetrabutylammonium fluoride solution (0.4 cc). (4R)-3-5 {3-{2-[4-tert-Butoxy-carbonyl-2-(5-methyl-2-thienyl)-3-thiazolidinyl]-2-oxoethyl}ureido}benzoic acid (A form) (0.08 g) is thus obtained in the form of an orange solid, m.p. at 85-90°C.

Proton NMR (300 MHz, DMSO D6 plus several 10 drops of CD3COOD, 6 in ppm, J in Hz), 2 rotamers at room temperature, characteristic chemical shifts at 120°C: 1.5 (s, 9H, -C(CH3)3; 2.46 (s, 3H, -CH3); 3.4 and 3.52 (2dd, J = 12 and 6.5, 1H each, -S-CHZ); 3.96 (d, J = 17.5, 1H, 1H of N-COCH2-N) ; 4.05 (d, J = 17.5, 1H, the 15 other H of N-COCH2-N); 4.96 (t, J= 6.5, 1H, OOC-CH-N) ; 6.65 (s, 1H, S-CH-N); 6.65 (d, J = 4, 1H, H in position 4 on thienyl); 7.12 (d, J = 4, 1H, H in position 3 on thienyl); 7.55 and 7.62 (2dd, J = 8 and 2, 1H each, H in position 4 and 6 on CO-NH-Ph-), 8.02 (t, J = 2, 1H, 20 H in position 2 on CO-NH-Ph-).

Infrared spectrum (KBr), characteristic bands in cm"1: 3390, 3100 to 3000, 2975, 2930, 2830, 2750-2300 (broad band), 1715, 1695, 1650, 1615, 1595, 1560, 1490, 1425, 1395, 1370, 1150, 800, 785, 755. 25 2-Trimethylsilylethyl (4R)-3-{3-[4-tert- butoxycarbonyl-2-(5-methyl-2-thienyl)-3-thiazolidinyl]-2-oxoethyl}ureido}benzoate (A form) may be prepared in 248 a fashion similar to that described in Example 41 A, but starting from tert-butyl (2RS,4R)-2-(5-methyl-2-thienyl)-4-thiazolidinecarboxylate (0.38 g), 2-{3-[3-(2-trimethylsilylethoxycarbonyl)phenyl]ureido)acetic acid (0.45 g) and N,N'-dicyclohexylcarbodiimide (0.30 g). The crude product is purified by chromatography on silica [eluent: ethyl acetate/ cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. 2-Trimethylsilylethyl (4R)-3-{3-[4-tert-butoxycarbonyl-. 2-(5-methyl-2-thienyl)-3-thiazolidinyl]-2-oxoethyl}-ureido}benzoate (A form) (0.12 g) is thus obtained in the form of an orange-yellow solid, used as it is in subsequent syntheses. tert-Butyl (2RS,4R)-2-(5-methyl-2-thienyl)-4-thiazolidinecarboxylate may be prepared in a fashion similar to that described in Example 48 B, but starting from tert-butyl (4R)-3-tert-butoxycarbonyl-2-(5-methyl-2-thienyl)-4-thiazolidinecarboxylate (A form) (1.0 g) and iodotrimethylsilane (0.38 cc). tert-Butyl (2RS,4R)-2-(5-methyl-2-thienyl)-4-thiazolidinecarboxylate (0.38 g) is thus obtained in the form of a yellow oil, used as it is in subsequent syntheses. tert-Butyl (4R)-3-tert-butoxycarbonyl-2-(5-methyl-2-thienyl)-4-thiazolidinecarboxylate (A form) may be prepared in a fashion similar to that described L T J- 249 in Example 48 C, but starting from 3-tert-butoxy-carbonyl-2-(5-methyl-2-thienyl)-4-thiazolidine-carboxylic acid (A form) (2.97 g), para-toluenesul-phonyl chloride (1.72 g) and tert-butanol (0.67 g). The crude product obtained is purified by chromatography on silica [eluent: ethyl acetate/cyclohexane (30/70 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C. tert-Butyl (4R)-3-tert-butoxy-carbonyl-2-(5-methyl-2-thienyl)-4-thiazolidinecarboxylate (A form) (1.0 g) is thus obtained in the form of an orange oil, used as it is in subsequent syntheses. 3-tert-Butoxycarbonyl-2-(5-methyl-2-thienyl)-4-(4R)-thiazolidinecarboxylic acid (A form) may be prepared in a fashion similar to that described in Example 48 D, but starting from 2-(5-methyl-2-thienyl)-4-thiazolidinecarboxylic acid (2.7 g), IN aqueous sodium hydroxide solution (11.9 cc) and di-tert-butyl dicarbonate (2.6 g). 3-tert-Butoxycarbonyl-2-(5-methyl-2-thienyl)-4-(4R)-thiazolidinecarboxylic acid (A form) (3.0 g) is thus obtained in the form of a yellow solid, used as it is in subsequent syntheses. 2-(5-Methyl-2-thienyl)-4-(2RS,4R)-thiazolidinecarboxylic acid may be prepared as in Example 34D, but starting from L-cysteine (10.0 g) and 5-methyl-2-thienylcarboxaldehyde (11.3 g). 2-(5-Methyl-2-thienyl)-4-(2RS,4R)-thiazolidinecarboxylic acid •1 ' (7.86 g) , m.p. 178°C, used as it is in subsequent syntheses, is thus obtained.

Example 111 The operation is carried out as in Example 84, but 5 starting from benzyl 2-{3-{3-[2-((2S,5R)-2-tert-butoxycarbony 1-5-phenyl- 1-pyrrolidiny 1) -2-oxoethyl]ureido}phenyl}propionate (B form) (0.88 g) in solution in ethyl acetate (50 cc) and 10 % palladium on charcoal (0.22 g). After treatment, 2-{3-{3-[2-((2S,5R)-2-10 tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2- oxoethyl]ureido}phenyl}propionic acid (B form) (0.5 g), m.p. 120°C, [a]j2,0 = +49.8 ± 0.8° (c = 0.53; methanol), is obtained.

Benzyl 2-{3-{3-[2-((2S,5R)-2-tert-butoxycarbonyl-5-15 phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}phenyl}propionate (B form) may be obtained in a fashion similar to that described in Example 2, but starting from tert-butyl (2S,5R)-1-(2-aminoacetyl)-5-phenylprolinate (0.79 g) and benzyl 2-(3-isocyanato-phenyl)propionate (B form) (0.8 g) 20 in tetrahydrofuran (40 cc). After treatment, benzyl 2-{3-{3-[2-((2S,5R)-2-tert-butoxycarbony1-5-phenyl-l-pyrrolidinyl) -2-oxoethyl]ureido}phenyl}propionate (0.9 g) , m.p. 75°C, is obtained.

A 251 tert-Butyl (2S,5R)-1-(2-aminoacetyl)-5-phenylprolinate may be obtained in a fashion similar to that described in Example 2 A, but starting from tert-butyl (2S,5R)-1-(2-tert-butoxycarbonylaminoacetyl)-5-phenylprolinate (1.22 g), iodotrimethylsilane (0.45 cc) in solution in anhydrous chloroform (30 cc). tert-Butyl (2S,5R)-l-(2-aminoacetyl)-5-phenylprolinate (0.79 g) is thus obtained in the form of an oil, used as it is in subsequent syntheses. tert-Butyl (2S,5R)-1-(2-tert-butoxy-carbonylaminoacetyl)-5-phenylprolinate may be obtained as per Example 2 B, but starting from a solution containing tert-butyl (2S,5R)-5-phenylprolinate (8 g), 2-tert-butoxycarbonylaminoacetic acid (5.7 g) and N, N' -dicyclohexylcarbodiimide (6.7 g) in anhydrous acetonitrile (75 cc). tert-Butyl (2S,5R)-1-(2-tert-butoxy-carbonylaminoacetyl)-5-phenylprolinate (10.5 g), m.p. 136 °C, [a]" = +1901 i 0.8° (c = 0.64; methanol), is thus obtained.

Example 112 The operation is carried out in a fashion similar to that described in Example 2, but starting from tert-butyl (2S,5R)-l-(2-aminoacetyl)-5-phenyl-prolinate (2.5 g), tetrabutylammonium (RS)-l-(3-iso-cyanatophenyl)ethanesulphonate (5 g) in tetrahydrofuran (60 cc). After treatment, potassium (2S,5R)-l-{3- 252 {3-[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}phenyl}ethanesulphonate (0.23 g), (mixture of the two 1-position epimers) is obtained in the form of an amorphous beige solid, [a]" = +20"7 +0.9° (c = 0.55; methanol).

Tetrabutylammonium (RS)-l-(3-isocyanatophenyl ) ethanesulphonate may be prepared as described in Example 21, but starting from tetrabutylammonium (RS)-l-(3-aminophenyl)ethanesulphonate (4.5 g) in toluene (40 cc), charcoal (0.2 g) and trichloromethyl chloroformate (1.21 cc). After treatment, tetrabutylammonium (RS)-1-(3-isocyanato-phenyl)ethanesulphonate (5 g) is obtained in the form of an oil, used as it is in subsequent syntheses.

Example 113 The operation is carried out in a fashion similar to that described in Example 2, but starting from tert-butyl (2S,5R)-1-(2-aminoacetyl)-5-phenyl-prolinate (2.6 g), tetrabutylammonium 3-isocyanato-phenylmethanesulphonate (4.8 g) in tetrahydrofuran (60 cc). After treatment, potassium (2S,5R)-l-{3--{3-[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl>ureido>phenyl}methanesulphonate (0.21 g), is obtained in the form of an amorphous beige solid, [<*]d° ~ +18°7 ±0.8° (c = 0.63; methanol). 253 Tetrabutylammonium 3-isocyanatophenyl-methanesulphonate may be prepared as described in Example 21, but starting from tetrabutylammonium (RS)-3-aminophenylmethanesulphonate (10 g) in toluene (80 cc), charcoal (0.49 g) and trichloromethyl chloroformate (2.85 cc). After treatment, tetrabutylammonium 3-isocyanatophenylmethanesulphonate (11 g) is obtained in the form of an oil, used as it is in subsequent syntheses.

Example 114 In an inert atmosphere methanol (20 cc) is slowly added to a flask containing benzyl 2-{3-{3-{2-[(2R,4R)-4-tert-butoxycarbonyl-2-(2,3-difluorophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido>phenyl}propionate (B form) (1.38 g), ammonium formate (0.85 g) and 10 % palladium on charcoal (1.38 g). The reaction mixture is heated under reflux for 1 hour, then cooled to a temperature in the vicinity of 25#C. The catalyst is then removed by filtration and the filtrate is concentrated to dryness under reduced pressure at 40°C. The residue obtained is dissolved in a 0.1N aqueous sodium hydroxide solution (20 cc) and washed with diethyl ether (2 x 10 cc). The aqueous phase is brought to a pH of 2 by addition of a IN aqueous sulphuric acid solution. The precipitated product is separated by filtration, washed with water (2 x 10 cc) and dried in 254 air. 2-{3-{3-{2-[(2R,4R)-4-tert-Butoxycarbonyl-2-(2,3-difluorophenyl)-3-thiazolidinyl]-2-oxoethyl} ureido}-phenyl}propionic acid (B form) (1.0 g), m.p. 130°C, is thus obtained. [cr]S° = +82° ±2 (C = 0.707 %; DMF) Benzyl 2-{3-{3-{2-[(2R,4R)-4-tert-butoxycarbonyl-2-(2, 3-difluorophenyl)-3-thiazolidinyl] 2-oxoethyl}ureido>phenyl}propionate (B form) may be prepared in a fashion similar to that described in Example 34, but starting from tert-butyl (2R,4R)-3-(2-aminoacetyl)-2-(2,3-difluorophenyl)-4-thiazolidine-carboxylate (2.5 g) and benzyl 2-(3-isocyanatophenyl)-propionate (B form) (1.96 g). The crude product is purified by chromatography on silica [eluent; ethyl acetate/cyclohexane (40/60 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40°C Benzyl 2-{3-{3-{2-[(2R,4R)-4-tert-butoxycarbonyl-2-(2, 3-difluorophenyl)-3-thiazolidinyl]-2-oxoethyl}-ureido}phenyl}propionate (B form) (1.8 g) is thus obtained in the form of an amorphous product, used as it is in subsequent syntheses.

Example 115 A solution of tert-butyl (cis)-{3-{3-[2-(2,5 diphenyl-1-pyrrolidinyl)-2- 255 oxoethyl]ureido}phenyl}methylene-aminooxyacetate (2.1 g) in solution in trichloroacetic acid (10 cc) is stirred for two hours at a temperature in the vicinity of 20°C, then the reaction medium is brought to dryness under reduced pressure at a temperature in the vicinity of 40°C. The residue is crystallised in water (50 cc), filtered, washed with water (3 x 15 cc) and dried at a temperature in the vicinity of 20"C. The product thus obtained is purified by chromatography on silica [eluent: dichloromethane/ methanol (95/5 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at a temperature in the vicinity of 35°C.

After recrystallisation in acetonitrile, (cis)-{3-{3-[2-(2,5-diphenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}-phenyl}-methylenaminooxyacetic acid (1 g), m.p. 194°C, is thus obtained. tert-Butyl (cis)-{3-{3-[2-(2,5-diphenyl-l-pyrrolidinyl )-2-oxoethyl]ureido}phenyl}-methylenaminooxyacetate may be obtained in a fashion similar to that described in Example 3, but starting from (cis)-1-(2-aminoacetyl)-2,5-diphenylpyrrolidine (4.2 g), N,N'-carbonyldiimidazole (1.78 g) and tert-butyl 3-aminophenylmethyleneaminooxyacetate (2.5 g) in 1,2-dichloroethane (60 cc). After treatment, tert-butyl (cis)-{3-{3-[2-(2,5-diphenyl-l-pyrrolidinyl)-2- 256 oxoethyl]ureido}phenyl}methylenaminooxyacetate (2.1 g) is obtained in the form of an amorphous beige solid. tert-Butyl 3-aminophenylmethyleneaminooxy-acetate may be obtained as follows: platinum oxide (0.75 g) is added to a solution of tert-butyl 3-nitro-phenylmethyleneaminooxyacetate (7.5 g) in ethanol (100 cc). The suspension is stirred for 1 hour at a temperature in the vicinity of 20°C under a hydrogen atmosphere (130 kPa). The catalyst is separated by filtration and the filtrate is concentrated to dryness under reduced pressure at 45°C. The residue is dissolved in ethyl acetate (50 cc) and the organic phase is washed with water (50 cc), dried over magnesium sulphate and concentrated under reduced pressure. tert-Butyl 3-aminophenylmethyleneaminooxy-acetate (6.2 g) is thus obtained in the form of an oil, used as it is in subsequent syntheses. tert-Butyl 3-nitrophenylmethyleneaminooxy-acetate may be obtained as follows: a 60 % solution of sodium hydride (4.3 g) in Vaseline is degreased by washing with hexane (2 x 50 cc). After addition of tetrahydrofuran (100 cc), the suspension is cooled to a temperature in the vicinity of 5°C and a solution of 3-nitrobenzaldoxime (4.98 g) in tetrahydrofuran (20 cc) is introduced dropwise. The reaction mixture is stirred for an hour at a temperature in the vicinity of 25°C, with the subsequent addition of tert-butyl bromoacetate 257 (6 g) in solution in tetrahydrofuran (5 cc), and stirring is continued for an hour at a temperature in the vicinity of 25°C. The reaction medium is then poured into a mixture of water (200 cc) and ethyl 5 acetate (100 cc). The organic phase is separated by decantation, dried over magnesium sulphate and concentrated to dryness under reduced pressure at a temperature in the vicinity of 40°C. tert-Butyl 3-nitrophenylmethyleneaminooxy-acetate (7.5 g), m.p. 120°C, is thus obtained. 3-Nitrobenzaldoxime may be prepared according . to the method described by T.M. Opryshko et al., Izv. Vyssh. Uchebn. Zaved., Khim. Khim. Tekhnol., 3^., 53 (1988).

Example 116 The operation is carried out as in Example 108, but from 2-{3-{3-(2-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-3-thiazolidinyl]-2-oxoethyl>ureido}-phenyl}propionic acid (B form) (0.5 g) 20 and Oxone* (1.0 g). The crude product obtained is purified by chromatography on silica [eluent: methylene chloride/ methanol (90/10 by volume)], collecting fractions (10 cc). Fractions 15 to 19 are combined and concentrated to dryness under reduced pressure at 40°C. 25 2-{3-{3-(2-[(IRS,2R,4R)-4-tert-Butoxycarbonyl-2-(2-fluorophenyl)-l-oxide-3-thiazolidinyl]-2- 258 oxoethyl>ureido}phenyl}propionic acid (B form) (0.2 g) is thus obtained in the form of an amorphous product. Fractions 9 to 14 are combined and concentrated to dryness under reduced pressure at 40°C. A mixture of 5 2-{3-{3-(2-[(IRS,2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-l-oxide-3-thiazolidinyl]-2-oxoethyl}ureido}phenyl}propionic acid (B form) and of 2-{3-{3-(2-[(2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-1-dioxide-3-thiazolidinyl] -2-10 oxoethyl)ureido}phenyl}propionic acid (B form) (0.1 g) is thus obtained.

Proton NMR (200 MHz, DMSO D6, 6 in ppm, J in Hz): at 120°C the mixture of the two diastereoisomers in the proportions 88-12 is observed, characteristic 15 chemical shifts at 120°C: 1.32 (d, J = 7.5, 3H, -CH3); 1.50 and 1.58 (2s, 9H in total, -C(CH3)3 of the preponderant isomer then of the less abundant isomer); 2.85 (t, J = 12.5, 0.88H, 1H of -S-CH2 for the preponderant isomer); 3.4 to 4.4 (m, 6,12H, -CH-C00, 20 the other H of -S-CH2 for the preponderant isomer, the -S-CH2 of the less abundant isomer and N-C0CHz-N); 4.8 (t, J = 8, 0.12H, S-CH-N of the less abundant isomer); 4.97 (dd, J = 12.5 and 5.0, 0.88H, S-CH-N of the preponderant isomer); 6.3 to 6.45 (m, 1H, -NHC0-); 6.5 25 and 6.6 (2s, 0.12H and 0.88H, S-CH-N of the less abundant isomer and of the preponderant isomer); 6.8 (bd, J = 8, 1H, in position 4 on CO-NH-Ph-); 7.0 to 7.6 259 (m, 6H, aromatic); 7.77 and 8.10 (t, J = 8, 0.12H and 0.88H, in position 6 on S-CH-Ph- for the less abundant isomer and for the preponderant isomer); 8.84 and 8.96 (2s, 0.88H and 0.12H, ArNHCO- for the preponderant isomer and for the less abundant isomer).

Infrared spectrum (KBr), characteristic bands in cm"1: 3380, 2975, 2930, 2650 to 2250 (broad band), 1735, 1650, 1610, 1595, 1560, 1490, 1455, 1370, 1230, 1150, 1050, 760, 700. 2-{3-{3-(2-[ (2R,4R) -4-tert-Butoxycarbonyl-2-(2-fluorophenyl)-l-oxide-3-thiazolidinyl]-2-oxoethyl}ureido}phenyl}propionic acid (B form) was separated from the mixture of 2-{3-{3-{2-[(1RS,2R,4R)-4-tert-butoxycarbonyl-2-(2-fluorophenyl)-l-oxide-3-thiazolidinyl]-2~oxoethyl}ureido}phenyl}propionic acid (B form) and of 2-{3-{3-{2-[(2R,4R) -^-tert-butoxycarbonyl^-(2-f luorophenyl )-l-dioxide-3-thiazolidinyl]-2-oxoethyl}ureido}phenyl}propionic acid (B form) by chromatography on silica [eluent: ethyl acetate/methanol (95/5 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 30°C. 2-{3-{3-{2-[(2R,4R)-4-tert-Butoxycarbonyl-2-(2-fluorophenyl)-l-dioxide-3-thiazolidinyl]-2-oxoethyl}ureido}phenyl}propionic acid (0.02 g) (B form) is thus obtained in the form of an amorphous product.

Proton NMR (200 MHz, DMSO D6( S in ppm): 1.3 (d, 3H, -CH3) ; 1.5 (s, 9H, -CH,)3); 3.6 (m, 2H, CH2-S02) , 4.0 to 43. (m, 3H, Ar-CH-COO and N-C0CH2-N) ; 4.8 (bt, 1H, N-CH-COO); 6.4 (bt, 1H, -NHCO-); 6.5 (s, 1H, S-CH-N); 6.8 (bd, in 5 position 4 on CO-NH-Ph-); 7.1 to 7.8 (m, 6H, aromatic); 8.1 (bt, 1H in position 6 on S-CH-Ph-); 8.8 (bs, 1H, ArNHCO-).

Infrared spectrum (KBr), characteristic bands in cm'1: 3380, 2975, 2930, 2650 to 2250 (broad band), 1735, 1650, 1610, 1595, 1560, 1490, 1455, 1370, 1345, 1230, 1150, 760, 10 700, 550.

The medicaments according to the invention consist of a compound of formula (I) in free form or in the form of an addition salt with a pharmaceutically acceptable acid, in the pure state or in the form of a composition in which 15 it is associated with any other pharmaceutically compatible product, which may be inert or physiologically active, e.g. a pharmaceutically acceptable carrier or coating. The medicaments according to the invention may be used orally, parenterally, rectally or topically.

Tablets, pills, powders (gelatin capsules, cachets) or granules may be used as solid compositions for oral administration. In these compositions, the active principle according to the invention is mixed with one or more inert diluents, such as starch, cellulose, sucrose, lactose or 25 silica, under an argon stream. These compositions may also contain substances other than diluents, for instance one or more lubricants such as magnesium stearate or talc, a 1 /. »<j> colouring agent, a coating (coated pills) or a glaze.

Pharmaceutically acceptable solutions, suspensions, emulsions, syrups and elixirs containing inert diluents such as water, ethanol, glycerol, vegetable oils or 5 paraffin oil may be used as liquid compositions for oral administration. These compositions may contain substances other than diluents, for example wetting agents, sweetening agents, thickening agents, flavouring agents or stabilising agents.

Sterile compositions for parenteral administration may preferably be aqueous or nonaqueous solutions, suspensions or emulsions. Water, propylene glycol, a polyethylene glycol, vegetable oils, in particular olive oil, injectable organic esters, for instance ethyl oleate 15 or other appropriate organic solvents may be used as solvent or carrier. These compositions may also contain adjuvants, in particular wetting agents, isotonicity agents, emulsifiers, dispersing and stabilising agents. Sterilisation can be carried out in a variety of ways, for 20 instance by asepticising filtration, by incorporating to the composition sterilising agents, by irradiation or by heating. They can also be prepared in the form of sterile solid compositions which can be dissolved at the time of use in sterile water or any other injectable sterile 25 medium.

Compositions for rectal administration are suppositories or rectal capsules which contain, besides the £ 4 3 5 1 active ingredient, excipients such as cocoa butter, semisynthetic glycerides or polyethylene glycols.

Compositions for topical administration may be for instance creams, lotions, eyewashes, mouthwashes, nasal 5 drops or aerosols.

In human therapy, the compounds according to the invention are particularly useful in the treatment and prevention of disorders linked to CCK and to gastrin at the level of the nervous system and of the gastro-intestinal 10 tract. These compounds may therefore be used in the treatment and prevention of psychoses, of anxiety disorders, of Parkinson's disease or tardive dyskinesia, of irritable colon syndrome, of acute pancreatitis, of ulcers, of intestinal motility disorders, of certain tumours 15 sensitive to CCK, of memory disorders, as analgesic agents, as potentiators of the analgesic activity of narcotic or nonnarcotic analgesic medicaments and as appetite regulators.

The dosage depends on the effect sought, on the 20 duration of the treatment and on the administration route used; it is generally between 0.05 g and 1 g per day for oral administration to an adult with each dose ranging from 10 mg to 500 mg of active substance.

Generally speaking, the doctor will determine the 2 5 appropriate dosage as a function of age, of weight and of all the other factors relevant to the subject to be treated. • r; / "7 r /. ^ 3 The following examples give an illustration of compositions according to the invention: EXAMPLE A Hard gelatin capsules with a 50 mg dosage of active 5 ingredient with the composition shown below are prepared using the usual technique: - (2RS,5SR)—3 — {3 —[2-(2-tert-Butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]- ureido}-3-phenylbenzoic acid 50 mg - Cellulose. 18 mg Lactose 55 mg Colloidal silica 1 mg - Sodium carboxymethyl starch 10 mg Talc 10 mg - Magnesium stearate 1 mg EXAMPLE B Tablets with a dosage of 50 mg of active ingredient with the composition shown below are prepared using the usual technique: 20 - (2R,5S)-3-{3-[2-(2-tert-Butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]- ureido}benzoic acid 50 mg Lactose 104 mg Cellulose 40 mg - Povidone 10 mg - Sodium carboxymethyl starch 22 mg Talc 10 mg * . : :■ 5 1 - Magnesium stearate 2 mg Colloidal silica 2 mg Mixture of hydroxymethylcellulose, glycerine, titanium oxide (72-3.5-24.5) 5 to complete 1 finished coated tablet 245 mg EXAMPLE C An injectable solution containing 10 mg of the active product with the following composition is prepared: - (2Px,4R)-3-{3-[2 - (4-tert-Butoxycarbonyl-10 2-pheny1-3-thiazolidinyl)-2-oxoethyl]- ureido}phenylacetic acid 10 mg - Benzoic acid 80 mg - Benzyl alcohol 0.06 cc - Sodium benzoate 80 mg - 95 % ethanol 0.4 cc - Sodium hydroxide 24 mg - Propylene glycol 1.6 cc - Water q.s 4 cc

Claims (17)

WHAT WE CLAIM IS:

1. A compound of formula: R N (I) I CO-CH —NH-CO-r3 in which - either R represents a methylene, ethylene, SO, S02 or CHOH radical or a sulphur atom, R, represents a pyridyl radical optionally substituted by one or more alkyl radicals, a furyl radical optionally substituted by one or more alkyl radicals, a thienyl radical optionally substituted by one or more alkyl radicals, a quinolyl radical optionally substituted by one or more alkyl radicals, a naphthyl radical optionally substituted by one or more alkyl radicals, an indolyl radical optionally substituted by one or more alkyl radicals, or a phenyl radical optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy, hydroxyl, nitro, amino, monoalkylamino, dialkylamino, alkoxycarbonyl, -CO-NR7Rg, -NH-CO-CH3, trifluoromethyl and trifluoromethoxy radicals, and R5 represents a hydrogen atom; - or R represents a methylene radical, R, represents a hydrogen atom and Rj represents a phenyl radical; 7 - 266 - - or R represents a radical CHR^ and R, and R5 each represent a hydrogen atom; - R2 represents an alkoxycarbonyl, cycloalkyloxycarbonyl, cycloalkylalkyloxycarbonyl, -CONRoRjo or phenyl 5 radical optionally substituted by one or more substituents chosen-from alkyl, alkoxy and hydroxyl radicals; - R3 represents a phenyl radical (optionally substituted by one or more substituents chosen from halogen atoms 10 and alkyl, alkoxy and alkylthio radicals), or a naphthyl, indolyl, quinolyl or phenylamino radical, the phenyl ring of which is optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy, alkylthio, trifluoromethyl, carboxyl, 15 alkoxycarbonyl, hydroxyl, nitro, amino, acyl, cyano, sulphamoyl, carbamoyl, hydroxyiminoalkyl, alkoxyiminoalkyl, hydroxyamino-carbonyl, alkoxyaminocarbonyl, 5-tetrazolyl, 5-tetrazolylalkyl, trifluoromethylsulphonamido, alkyl-sulphinyl, mono- or 20 polyhydroxyalkyl, sulpho, -alk-O-CO-alk, -alk-COOX, -alk-O-alk, -alk'-COOX, -O-alk-COOX, -CH=CH-COOX, -CO-COOX, -alk-S03H optionally in the form of a salt, -CH=CH-alk', -C(=N0H)-COOX, -S-alk'-COOX, -0-CH2-alk'-C00X, -CX=N-0-alk-C00X, -alk-N(OH)-CO-alk and 2,2-dimethyl-25 4,6-dioxo-l,3-dioxan-5-yl radicals; - Rj represents a hydrogen atom or an alkyl radical; - Rft represents a phenyl radical; 24 3 5 14 - 267 - - R7 represents a hydrogen atom or an alkyl, phenylalkyl or phenyl radical optionally substituted by one or more substituents chosen from halogen atoms and alkylj, alkoxy and alkylthio radicals; and 5 - Rj represents an alkyl, phenylalkyl or phenyl radical optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy and alkylthio radicals; or R7 and form with the nitrogen atom to which they 10 are attached a mono- or polycyclic, saturated or unsaturated heterocycle containing 4 to 9 carbon atoms and one or more hetero atoms and optionally substituted by one or more alkyl radicals; - R^ represents a hydrogen atom or an alkyl, cycloalkyl-15 alkyl, cycloalkyl, phenylalkyl or phenyl radical optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy and alkylthio radicals; and - Rm represents an alkyl, cycloalkylalkyl, cycloalkyl, 20 phenylalkyl or phenyl radical optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy and alkylthio radicals; or R, and R10 form with the nitrogen atom to which they are attached a mono- or polycyclic, saturated or 25 unsaturated heterocycle containing 4 to 9 carbon atoms - X represents a hydrogen atom, or an alkyl or phenylalkyl radical; - alk represents (when monovalent) an alkyl or (when divalent) an alkylene radical; and 5 - alk' represents (when monovalent) a hydroxyalkyl or alkoxyalkyl radical, or (when divalent) a hydroxyalkylene or alkoxyalkylene radical, it being understood that the alkyl, alkylene and alkoxy radicals and the alkyl, alkylene and alkoxy moieties contain 1 to 4 carbon atoms each in a straight or 10 branched chain, the acyl radicals and moieties contain 2 to 4 carbon atoms each, and the cycloalkyl radicals and moieties contain 3 to 6 carbon atoms each, and its salts, and .its racemic mixtures and enantiomers when it comprises at least one asymmetric centre. 15

2. A compound of formula (,J) according to claim 1 wherein R7 and Rs form with the nitrogen atom to which they are attached a mono or polycyclic, saturated or unsaturated heterocycle containing 4 to 9 carbon atoms and one or more oxygen or nitrogen atoms and optionally substituted by one or 20 more alkyl radicals.

3. A compound of formula (I) according to claim 1 or 2 wherein R, and Rl0 form with the nitrogen atom to which they are attached a mono- or polycyclic, saturated or unsaturated heterocycle containing 4 to 9 carbon atoms and one or more 25 oxygen, nitrogen or sulphur atoms and optionally substituted by one or more alkyl radicals.

4. A compound of formula (I) according to claim 1, 2 or 3 in which R represents a methylene radical, a sulphur atom, or an SO radical, R, represents a phenyl radical which is 30 optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy, hydroxyl, nitro, amino, monoalkylamino, dialkylamino, alkoxycarbonyl, -C0-NR7Rg/ -NH-CO-CH3,trifluoromethyl and trifluoromethoxy radicals, R2 represents a phenyl or alkoxycarbonyl radical, R3 represents a phenylamino 35 radical, the phenyl ring of which is substituted by a carboxyl, -alk-COOH, -S-alk-COOH, hydroxyalkyl, -alk'-COOH, -alk-S03', or hydroxyiminoalkyl radical, R4 represents a hydrogen atom and R5 represents a hydrogen atom; wherein alk and alk' are as defined in claim 1. . . H , ' s 40 5. A compound of formula (I) according to claim 1 //^y which is / ' '' 24 3 5 J - 269 - - tert-butyl (2RS,5SR)-l-{2-[3-(3-((RS)-1-hydroxyethyl)-phenyl)ureido]acetyl}-5-phenylprolinate, - 2 — {3 — {3—[2 — ((2S,5R)-2-tert-butoxycarbony1-5-pheny1-1-pyrrolidinyl)-2-oxoethyl]ureido}phenylJpropionic acid 5 (B form), - (2RS,5SR)—{3—{3—[2-(2-tert-butoxycarbonyl-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}phenylthio}acetic acid, (2R,4R)-3-{3-(2-(4-tert-butoxycarbonyl-2-(2-fluoro-3-thiazolidinyl))-2-oxoethyl]ureido}phenylacetic acid, 10 - 2-{3-{3-[2-((2R,4R)-2-tert-butoxycarbony1-2-(2- fluoro-phenyl)-3-thiazolidinyl)-2-oxoethyl]ureido}-phenyl}propionic acid (B form), - potassium (RS)-l-{3-{3-[2-( (2R,4R)-4-tert-butoxy-carbony1-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido}- 15 phenyl}ethanesulphonate, mixture of A and B forms, - potassium (RS)—l — {3 — {3—[2 — ((2S,5R)-2-tert-butoxy-carbony1-5-phenyl-l-pyrrolidinyl)-2-oxoethyl]ureido}-phenyl}ethanesulphonate, - potassium (2S,5R)-l-{3-{3-[2-(tert-butoxycarbonyl-5-20 phenyl-1-pyrrolidinyl)-2-oxoethyl]ureido}phenyl}- methanesulphonate, - (2S,5R)-3-{3-[2-(2-tert-butoxycarbony1-5-phenyl-l-pyrrolidinyl) -2-oxoethyl]ureido}benzoic acid, - (2RS,5SR)-3-{3-{2-[2-tert-butoxycarbonyl-5-(2- 25 fluorophenyl)-1-pyrrolidinyl)-2-oxoethyl}ureido}benzoic acid, /? r { 24 35 14 - 270 - - cis-3-{ 3- [2- (2, 5-diphenyl-l-pyrrolidinyl) -2-oxoethyl]ureido}benzoic acid, - (2RS, 5RS) -3-{2-[2- (2-hydroxyphenyl) -5-phenyl-l-pyrrolidinyl] -2-oxoureido} pheny lacetic acid,

5 - (2R,4R) -3-{3-[2-(4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido}phenylacetic acid, - (2R, 4R) -3-{3-[2-(4-tert-butoxycarbonyl-2-phenyl-3-thiazolidinyl)-2-oxoethyl]ureido)benzoic acid, - 2 — {3 — {3 — [2—( (IRS, 2R, 4R) -4-tert-butoxycarbonyl-2- (2-10 f luorophenyl) -l-oxide-3-thiazoli,dinyl) -2-oxoethyl] - ureido}phenyl}propionic acid (A form), - (2R, 4R) —3 — { 3 — [ 2 - (4-tert-butoxycarbonyl-2 - (2 , 3-di-f luorophenyl) -3-thiazolidinyl) -2-oxoethyl]ureido)-phenylacetic acid or 15 - tert-butyl (2RS, 5SR)-l-{2-{3-[ (E)-3-(1-hydroxyimino-ethyl) phenyl]ureido}acetyl}-5-phenylprolinate, or (as the case may be) a corresponding acid, salt or ester thereof.

6. Process for preparing a compound of 20 formula (I) according to any one of claims 1 to 5 in which R represents a methylene, ethylene, CHOH or CHR<, radical or a sulphur atom and R3 represents a phenyl-amino radical, the phenyl ring of which is optionally substituted by one or more substituents chosen from halogen atoms and alkyl, 25 alkoxy and alkylthio radicals, which comprises reacting a reactive derivative of carbamic acid, obtained optionally in situ by action of a reactive derivative of carbonic acj^L— chosen from N, N'-carbonyldi imidazo] e, ,<■/y f X- ? r Yt ^ C t - 271 - phosgene, diphosgene and p-nitropheny1 chloroformate, with a compound of formula R R R5 1 ^2 'N I CO-CH-NH2 (ii) r4 in which R represents a methylene, ethylene, CHOH or 5 CHR<, radical or a sulphur atom and R,, R2, R^, R5 and-have the same meanings as in claim 1, with an aniline in which the phenyl ring is optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy, alkylthio, 10 trifluoromethyl, carboxyl, alkoxycarbonyl, hydroxyl, nitro, amino, acyl, cyano, sulphamoyl, carbamoyl, hydroxyiminoalkyl, alkoxyiminoalkyl, hydroxyaminocarbonyl, alkoxyaminocarbonyl, 5-tetrazoly1, 5-tetrazolylalkyl, trifluoromethyl-15 sulphonamido, alkylsulphinyl, mono- or poly- hydroxyalkyl, sulpho, -alk-O-CO-alk, -alk-COOX, -alk-0-alk, -alk'-COOX, -O-alk-COOX, -CH=CH-C00X, -CO-COOX, -alk-SOjH, -CH=CH-alk', -C(=NOH)-COOX, -S-alk-COOX, -0-CH2-alk'-COOX, -CX=N-0-alk-C00X, 20 -alk-N(OH)-CO-alk and 2,2-dimethyl-4,6-dioxo-l,3-dioxan-5-yl radicals wherein X, alk and alk' are as defined in claim 1; isolating the product obtained and optionally converting it into a salt.

7. Process according to claim 6, in which the reaction is carried out in an inert organic solvent 24 3 5 1 A - 272 - at a temperature of between 20°C and the boiling point of the solvent.

8. Process for preparing a compound of formula (I) according to any one of claims 1 to 5 in which R represents a 5 methylene, ethylene, CHOH or CHRs radical or a sulphur atom, wherein R^ is as defined in claim 1 and R3 represents a phenylamino radical, the phenyl ring of which is optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy, alkylthio, trifluoromethyl, hitro, 10 acyl, cyano, sulphamoyl, alkoxycarbonyl, -alk-0-alk, trifluoromethylsulphonamido, -alk-S03H optionally in the form of a salt, alk-COOX and alk'-COOX radicals in which X, alk and alk' are as defined in claim 1 wherein X is other than a hydrogen atom, which comprises 15 reacting a compound of formula (II) according to claim 6 with a phenyl isocyanate, the phenyl ring of which is optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy, alkylthio, trifluoromethyl, nitro, acyl, cyano, sulphamoyl, alkoxycarbonyl, -alk-O-alk, 20 trifluoromethylsulphonamido, -alk-S0,H, -alk-COOX and -alk'-COOX radicals wherein alk and alk' are as defined in claim 1, isolating the product obtained, and optionally converting it into a salt.

9. Process according to claim 8, in which the reaction 2 5 is carried out in an inert organic solvent at a temperature of between 10°C and the boiling temperature point of the solvent.

10. Process for preparing a compound of formula (I) * according to any one of claims 1 to 5 in which R represents//^ ' A * methylene, ethylene, CHOH or CHRh radical or a sulphur ato#,, 24 3? 1* 273 wherein R6 is as defined in claim 1 and R3 represents a phenylamino radical, the phenyl ring of which is substituted by a carboxyl, -alk-COOH, -O-alk-COOH, -alk'-COOH, -CH=CH=COOH, -CO-COOH, -S-alk-COOH, -C(=NOH)-COOH, -0-CH2-alk'-COOH. or -CX=N-5 O-alk-COOH radical wherein alk, alk' and X are as defined in claim 1; which comprises hydrolysing or hydrogenolysing a corresponding ester, isolating the product obtained, and optionally converting it into a salt. 10 according to any one of claims 1 to 5 in which R represents a methylene, ethylene, CHOH or CHR^ radical or a sulphur atom, wherein Ra is as defined in claim 1 and R3 represents an optionally substituted phenyl radical, a naphthyl radical, an indolyl radical, a quinolyl radical or a phenylamino radical, 15 the phenyl ring of which is optionally substituted by one or more substituents chosen from halogen atoms and alkyl, alkoxy, alkylthio, trifluoromethyl, nitro, acyl, cyano, sulphamoyl, alkoxycarbonyl, trifluoromethylsulphonamido, -alk-O-alk, -alk-COOX and -alk'-COOX radical's, wherein alk, alk' and X are as 20 defined in claim 1 and in which X is other than a hydrogen atom, which comprises reacting an acid of formula:

11. Process for preparing a compound of formula (I) 25 (IV) H \ " X- 5- y. 2435 274 in which R is defined as above and R , R„ and r are defined 1 2. D as in claim 1, with an acid of formula: HOOC-CH-NH-CO-R 5 in which R3 is defined as above and R, is defined as in claim 1, or with a reactive derivative of this acid, isolating the product obtained and optionally converting it into a salt. formula (I) according to any one of claims 1 to 5 in which R represents SO or SO,, which comprises oxidising a corresponding compound in which R represents a sulphur atom, isolating the product, and optionally 15 converting it into a salt. a compound of formula (I) according to any one of claims 1 to 5, which comprises subjecting said compound to a chromatographic operation on a chiral phase 20 defined by the structure: 10

12. Process for preparing a compound of

13. Process for separating an enantiomer of t 275 in which the symbols R', being identical or different, and R", being identical or different, represent alkyl radicals 5 containing 1 to 10 carbon atoms, G1 represents an electro-attractive group and n represents an integer from 3 to 13 inclusive. ~

14. A medicament comprising, as active principle, at least one compound according to any one of claims 1 to 5. 10

15. A medicament according to claim 14, for use in the treatment of disorders linked to CCK and to gastrin.

16. Process for the production of a compound as claimed 15 in claim 1 substantially as described in any one of the foregoing Examples 1 to 116.

17. A compound as claimed in claim 1 when produced by a process as claimed in any one of claims 6 to 13 and 16. Dy the ; • A J PA::.